Search results for: energy-saving in the external shell

Authors: Sulaiman Al-Hinai, Setyawan Widyarto

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The aim of this study is to identify the critically dominating factors on the delays of road constructions in the GCC countries and their effects on project delivery in Arab countries. Towards the achieved of the objectives the study used the empirical literature from the all relevant online sources and database as many as possible. The findings of this study have summarized and short listed of the success factors in the two categories such as internal and external factors have caused to be influenced to delay of road constructions in the Arab regions. However, in the category of internal factors, there are 63 factors short listed from seven group of factors which has revealed to effects on the delay of road constructions especially, the consultant related factors, the contractor related factors, designed related factors, client related factors, labor related factors, material related issues, equipment related issues respectively. Moreover, for external related factors are also considered to summarized especially natural disaster (flood, hurricanes and cyclone etc.), conflict, war, global financial crisis, compensation delay to affected property owner, price fluctuated, unexpected ground conditions (soil and high-water level), changing of government regulations and laws, delays in obtaining permission from municipality, loss of time by traffic control and restrictions at job site, problem with inhabitant of community, delays in providing service from utilities (water and electricity’s) and accident during constructions accordingly. The present study also concluded the effects of above factors which has delay road constructions through increasing of cost and overrun it, taken overtime, creating of disputes, going for lawsuits, finally happening of abandon of projects. Thus, the present study has given the following recommendations to overcome of above problems by increasing of detailed site investigations, ensure careful monitoring and regular meetings, effective site management, collaborative working and effective coordination’s, proper and comprehensive planning and scheduling and ensure full and intensive commitment from all parties accordingly.

Keywords: Arab GCC countries, critical success factors, road constructions delay, project management

Procedia PDF Downloads 115

Authors: Nikolaos Petropoulos, Elena Blokhina, Andrii Sokolov, Andrii Semenov, Panagiotis Giounanlis, Xutong Wu, Dmytro Mishagli, Eugene Koskin, Robert Bogdan Staszewski, Dirk Leipold

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We investigate entanglement and quantum information scrambling (QIS) by the example of a many-body Extended and spinless effective Fermi-Hubbard Model (EFHM and e-FHM, respectively) that describes a special type of quantum dot array provided by Equal1 labs silicon-based quantum computer. The concept of QIS is used in the framework of quantum information processing by quantum circuits and quantum channels. In general, QIS is manifest as the de-localization of quantum information over the entire quantum system; more compactly, information about the input cannot be obtained by local measurements of the output of the quantum system. In our work, we will first make an introduction to the concept of quantum information scrambling and its connection with the 4-point out-of-time-order (OTO) correlators. In order to have a quantitative measure of QIS we use the tripartite mutual information, in similar lines to previous works, that measures the mutual information between 4 different spacetime partitions of the system and study the Transverse Field Ising (TFI) model; this is used to quantify the dynamical spreading of quantum entanglement and information in the system. Then, we investigate scrambling in the quantum many-body Extended Hubbard Model with external magnetic field Bz and spin-spin coupling J for both uniform and thermal quantum channel inputs and show that it scrambles for specific external tuning parameters (e.g., tunneling amplitudes, on-site potentials, magnetic field). In addition, we compare different Hilbert space sizes (different number of qubits) and show the qualitative and quantitative differences in quantum scrambling as we increase the number of quantum degrees of freedom in the system. Moreover, we find a "scrambling phase transition" for a threshold temperature in the thermal case, that is, the temperature of the model that the channel starts to scramble quantum information. Finally, we make comparisons to the TFI model and highlight the key physical differences between the two systems and mention some future directions of research.

Keywords: condensed matter physics, quantum computing, quantum information theory, quantum physics

Procedia PDF Downloads 84

Authors: Mitchell Gohnert, Ryan Bradley

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This paper reviews some fundamental concepts of structural optimization, which are based on the type of materials used in construction and the shape of the structure. The first step in structural optimization is to break down all internal forces in a structure into fundamental stresses, which are tensions and compressions. Knowing the stress patterns directs our selection of structural shapes and the most appropriate type of construction material. In our selection of materials, it is essential to understand all construction materials have flaws, or micro-cracks, which reduce the capacity of the material, especially when subjected to tensions. Because of material defects, many construction materials perform significantly better when subjected to compressive forces. Structures are also more efficient if bending moments are eliminated. Bending stresses produce high peak stresses at each face of the member, and therefore, substantially more material is required to resist bending. The shape of the structure also has a profound effect on stress levels. Stress may be reduced dramatically by simply changing the shape. Catenary, triangular and linear shapes are the fundamental structural forms to achieve optimal stress flow. If the natural flow of stress matches the shape of the structures, the most optimal shape is determined.

Keywords: arches, economy of stresses, material strength, optimization, shells

Procedia PDF Downloads 103

Authors: Ketankumar Gandabhai Patel, Jalpit Balvantkumar Prajapati

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Plate type heat exchangers has many thin plates that are slightly apart and have very large surface areas and fluid flow passages that are good for heat transfer. This can be a more effective heat exchanger than the tube or shell heat exchanger due to advances in brazing and gasket technology that have made this plate exchanger more practical. Plate type heat exchangers are most widely used in food processing industries and dairy industries. Mostly fouling occurs in plate type heat exchanger due to deposits create an insulating layer over the surface of the heat exchanger, that decreases the heat transfer between fluids and increases the pressure drop. The pressure drop increases as a result of the narrowing of the flow area, which increases the gap velocity. Therefore, the thermal performance of the heat exchanger decreases with time, resulting in an undersized heat exchanger and causing the process efficiency to be reduced. Heat exchangers are often over sized by 70 to 80%, of which 30 % to 50% is assigned to fouling. The fouling can be reduced by varying some geometric parameters and flow parameters. Based on the study, a correlation will estimate for Nusselt number as a function of Reynolds number, Prandtl number and chevron angle.

Keywords: heat transfer coefficient, single phase flow, mass flow rate, pressure drop

Procedia PDF Downloads 302

Authors: Ashok D. Satpute

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Ayurveda, the ancient Indian Medical system is practiced all over India and abroad, is rich in natural source of medicines, including marine products. The marine drugs which prominently used are pravala (coral), mukta (pearl), kapardika (cowry).Shukti (oyster shell), shankha (conch), agnijara (amber) etc. Except agnijara (amber) all are rich in calcium. Interestingly they are not used as supplements in calcium deficiency as done in conventional medical practice. They are used as medicines in the disease like fever, tuberculosis, bleeding disorders, eye problems, digestive complaints etc. Many scientific studies have shown their potent medicinal value. Each has its own properties and used therapeutically after subjecting them to various purificatory processes which are called shodhana in which several medicinal plants are used which also help in enhancing therapeutical activity. Then these purified marine products are subjected to marana (incineration) process and obtained in the form of Bhasma (a finest form of medicine). Agnijara, a derivative of whale is useful as aphrodisiac and prescribed in neuromuscular disorders and tetanus. The ancient scriptures written in Sanskrit language thousands of years back have rich information about all these natural marine products and their medicinal usage.

Keywords: Ayurveda, bhasma, marana, shodhana

Procedia PDF Downloads 265

Authors: Jegede Oluseye Oladayo

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The study mapped innovation activities in the formal and informal mining sector in Nigeria. Data were collected through primary and secondary sources. Primary data were collected through guided questionnaire administration, guided interviews and personal observation. A purposive sampling method was adopted to select firms that are micro, small and medium enterprises. The study covered 100 (50 in the formal sector and 50 in the informal sector) purposively selected companies in south-western Nigeria. Secondary data were collected from different published sources. Data were analysed using descriptive and inferential statistics. Of the four types of technological innovations sampled, organisational innovation was found to be highest both in the formal (100%) and informal (100%) sectors, followed by process innovation: 60% in the formal sector and 28% in the informal sector, marketing innovation and diffusion based innovation were implemented by 64% and 4% respectively in the formal sector. There were no R&D activities (intramural or extramural) in both sectors, however, innovation activities occur at moderate levels in the formal sector. This is characterised by acquisition of machinery, equipment, hardware (100%), software (56), training (82%) and acquisition of external knowledge (60%) in the formal sector. In the informal sector, innovation activities were characterised by acquisition of external knowledge (100%), training/learning by experience (100%) and acquisition of tools (68%). The impact of innovation on firm’s performance in the formal sector was expressed mainly as increased capacity of production (100%), reduced production cost per unit of labour (88%), compliance with governmental regulatory requirements (72%) and entry on new markets (60%). In the informal sector, the impact of innovation was mainly expressed in improved flexibility of production (70%) and machinery/energy efficiency (70%). The important technological driver of process innovation in the mining sector was acquisition of machinery which accounts for the prevalence of 100% both in the formal and informal sectors. Next to this is training and re-training of technical staff, 74% in both the formal and the informal sector. Other factors influencing organisational innovation are skill of workforce with a prevalence of 80% in both the formal and informal sector. The important technological drivers include educational background of the manager/head of technical department (54%) for organisational innovation and (50%) for process innovation in the formal sector. The study concluded that innovation competence of the firms was mostly organisational changes.

Keywords: innovation prevalence, innovation activities, innovation performance, innovation drivers

Procedia PDF Downloads 368

Authors: S. Summart, C. Saetiaw, T. Thosdeekoraphat, C. Thongsopa

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This article presents new current-mode oscillator circuits using CDTAs which is designed from block diagram. The proposed circuits consist of two CDTAs and two grounded capacitors. The condition of oscillation and the frequency of oscillation can be adjusted by electronic method. The circuits have high output impedance and use only grounded capacitors without any external resistor which is very appropriate to future development into an integrated circuit. The results of PSPICE simulation program are corresponding to the theoretical analysis.

Keywords: current-mode, quadrature oscillator, block diagram, CDTA

Procedia PDF Downloads 447

Authors: Kingsley Izuagbe Ikeke, Abayomi O. Adetuyi

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The study investigated the removal efficiency of crystal violet from aqueous solution using chitosan-charcoal composite as adsorbent. Deproteination was carried out by placing 200g of powdered snail shell in 4% w/v NaOH for 2hours. The sample was then placed in 1% HCl for 24 hours to remove CaCO3. Deacetylation was done by boiling in 50% NaOH for 2hours. 10% Oxalic acid was used to dissolve the chitosan before mixing with charcoal at 55°C to form the composite. The composite was characterized by Fourier Transform Infra-Red and Scanning Electron Microscopy measurements. The efficiency of adsorption was evaluated by varying pH of the solution, contact time, initial concentration and adsorbent dose. Maximum removal of crystal violet by composite and activated charcoal was attained at pH10 while maximum removal of crystal violet by chitosan was achieved at pH 8. The results showed that adsorption of both dyes followed the pseudo-second-order rate equation and fit the Langmuir and Freundlich isotherms. The data showed that composite was best suited for crystal violet removal and also did relatively well in the removal of alizarin red. Thermodynamic parameters such as enthalpy change (ΔHº), free energy change (ΔGº) and entropy change (ΔSº) indicate that adsorption process of Crystal Violet was endothermic, spontaneous and feasible respectively.

Keywords: crystal violet, chitosan−charcoal composite, extraction process, sorption

Procedia PDF Downloads 422

Authors: M. Sneha, N. Meenakshi Sundaram

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In recent times, magnetic hyperthermia is used for cancer treatment as a tool for active targeting of delivering drugs to the targeted site. It has a potential advantage over other heat treatment because there is no systemic buildup in organs and large doses are possible. The aim of this study is to develop a suitable magnetic biomaterial that can destroy the cancer cells as well as induce bone regeneration. In this work, the composite material was synthesized in two-steps. First, porous iron oxide nano needles were synthesized by hydrothermal process. Second, the hydroxyapatite, were synthesized from natural calcium (i.e., egg shell) and inorganic phosphorous source using wet chemical method. The crystalline nature is confirmed by powder X-ray diffraction analysis (XRD). Thermal analysis and the surface area of the material is studied by Thermo Gravimetric Analysis (TGA), Brunauer-Emmett and Teller (BET) technique. Scanning electron microscope (SEM) images show that the particles have nanoneedle-like morphology. The magnetic property is studied by vibrating sample magnetometer (VSM) technique which confirms the superparamagnetic behavior. This paper presents a simple and easy method for synthesis of magnetite/hydroxyapatite composites materials.

Keywords: iron oxide nano needles, hydroxyapatite, superparamagnetic, hyperthermia

Procedia PDF Downloads 635

Authors: Sandra T. Matarneh, Mark Danso-Amoako, Salam Al-Bizri, Mark Gaterell

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Today’s facilities are ever more sophisticated and the need for available and reliable information for operation and maintenance activities is vital. The key challenge for facilities managers is to have real-time accurate and complete information to perform their day-to-day activities and to provide their senior management with accurate information for decision-making process. Currently, there are various technology platforms, data repositories, or database systems such as Computer-Aided Facility Management (CAFM) that are used for these purposes in different facilities. In most current practices, the data is extracted from paper construction documents and is re-entered manually in one of these computerized information systems. Construction Operations Building information exchange (COBie), is a non-proprietary data format that contains the asset non-geometric data which was captured and collected during the design and construction phases for owners and facility managers use. Recently software vendors developed add-in applications to generate COBie spreadsheet automatically. However, most of these add-in applications are capable of generating a limited amount of COBie data, in which considerable time is still required to enter the remaining data manually to complete the COBie spreadsheet. Some of the data which cannot be generated by these COBie add-ins is essential for facilities manager’s day-to-day activities such as job sheet which includes preventive maintenance schedules. To facilitate a seamless data transfer between BIM models and facilities management systems, we developed a framework that enables automated data generation using the data extracted directly from BIM models to external web database, and then enabling different stakeholders to access to the external web database to enter the required asset data directly to generate a rich COBie spreadsheet that contains most of the required asset data for efficient facilities management operations. The proposed framework is a part of ongoing research and will be demonstrated and validated on a typical university building. Moreover, the proposed framework supplements the existing body of knowledge in facilities management domain by providing a novel framework that facilitates seamless data transfer between BIM models and facilities management systems.

Keywords: building information modeling, BIM, facilities management systems, interoperability, information management

Procedia PDF Downloads 102

Authors: Abhimanyu Behera

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Over the past few years, energy security and sustainable development have moved rapidly into the global agenda. There are two main reasons: first, the impact of high and often volatile energy prices; second, concerns over environmental sustainability particularly about the global climate. Both issues are critically important in which impressive economic growth has boosted the demand for energy and put corresponding strains on the environment. Energy security is a broad concept that focuses on energy availability and pricing. Specifically, it refers to the ability of the energy supply system i.e. suppliers, transporters, distributors and regulatory, financial and R&D institutions to deliver the amount of competitively priced energy that customers demand, within accepted standards of reliability, timeliness, quality, safety. Traditionally, energy security has been defined in the context of the geopolitical risks to external oil supplies but today it is encompassing all energy forms, all the external and internal links bringing the energy to the final consumer, and all the many ways energy supplies can be disrupted including equipment malfunctions, system design flaws, operator errors, malicious computer activities, deficient market and regulatory frameworks, corporate financial problems, labour actions, severe weather and natural events, aggressive acts (e.g. war, terrorism and sabotage), and geopolitical disruptions. In practice, the most challenging disruptions are those linked to: 1) extreme weather events; 2) mismatched electricity supply and demand; 3) regulatory failures; and 4) concentration of oil and gas resources in certain regions of the world. However, insecure energy supplies inhibit development by raising energy costs and imposing expensive cuts in services when disruptions actually occur. The energy supply sector can best advance sustainable development by producing and delivering secure and environmentally-friendly sources of energy and by increasing the efficiency of energy use. With this objective, this paper seeks to highlight the significance of energy security and sustainable development in today’s world. Moreover, it critically overhauls the major challenges towards sustainability of energy security and what are the major policies are taken to overcome these challenges by Government is lucidly explicated in this paper.

Keywords: energy, policies, security, sustainability

Procedia PDF Downloads 377

Authors: Apurva Sapra

Abstract:

The aim of this research was to study and compare the nature of expected, feared and hoped-for selves in institutionalized adolescent boys in two residential settings – an observation home with children in conflict with the law, and a children’s home with children in need of care and protection. The study uses a concurrent mixed methods design, in which eight adolescent boys from each group, aged 13-17, were asked to respond to a questionnaire, followed by an in-depth interview. The questionnaire looked into the total scores on current, probable and hoped-for/feared positive and negative self-descriptors. Possible selves of both groups were found to be influenced by their unique histories, such as with their experience of violence, interaction with the police and emphasis given on education. Expected selves and hoped-for selves were similar within the two groups. However, they were more concrete and attainable in the observation home and more ambitious in the children’s home. Quantitative results showed that on the positive self-descriptors, the participants in the observation home had a slightly lower total score on the current parameter as on the probable and hoped-for parameters. The participants in the children’s home showed similar results on current and probable positive self-descriptors, with higher scores on the hoped-for parameter. For most of the negative self-descriptors, the current score for the observation home group was lower than the expected score, and for the children’s home group, they were feared slightly more than they were expected. Along with the nature of possible selves, the study also looked into threats and support to desired and feared possible selves, as well as strategies to attain the desired possible selves and avoid feared possible selves. While threats to possible selves were identified as external and internal in both groups, the participants in the children’s home tended to identify threats as external. The categories of support were similar across the two groups, although the nature of support provided differed. Strategies adopted by participants in the observation home could be clearly divided as past, present and future strategies, while those adopted by participants in the children’s home had an overlap with past and future strategies. The institution was perceived as having a negative influence for the future in the observation home group, but positive in the children’s home group. Limitations of the study and recommendations for future research, policy setting and the counselling profession are discussed.

Keywords: adolescents, expected self, feared self, hoped-for self, institutions, possible selves

Procedia PDF Downloads 223

Authors: Moudar Zgoul, Hashem Alkhaldi

Abstract:

A large number of transportable LPG cylinders are manufactured annually for domestic use. These LPG cylinders are manufactured from mild steel and filled maximally with 12.5 kg liquefied gas under internal pressure of 0.6 N/mm² at a temperature of 50°C. Many millions of such LPG cylinders are in daily use mainly, for purposes of space heating, water heating, and cooking. Thereby, they are imposed to severe conditions leading to their failure. Each year not less than 5000 of these LPG cylinders fail, some of those failures cause damage and loss in lives and properties. In this work, LPG cylinders were investigated; Stress calculations and deformations under dynamic (impact) loadings were carried out to simulate the effects of such loads on the cylinders while in service. Analysis of the LPG cylinders was carried out using the finite element method; shell and cylindrical elements were used at the top, bottom, and in middle (weld region), permitting elastic-plastic analysis for a thin-walled LPG cylinder. Variables such as maximum stresses and maximum deflections under the effect of impact loading were investigated in this work. Results showed that the maximum stresses reach 680 MPa when dropped from 3m-height. The maximum radial deformation occurs at the cylinder’s top in case of the top-position impact. This information should be useful for enhancing the strength of such cylinders and to for prolonging their service life.

Keywords: dynamic analysis, finite element method, impact load, LPG cylinders

Procedia PDF Downloads 311

Authors: Mitchell Gohnert

Abstract:

This paper reviews some fundamental concepts of structural optimization, which is based on the type of materials used in construction and the shape of the structure. The first step in structural optimization is to break down all internal forces in a structure into fundamental stresses, which are tensions and compressions. Knowing the stress patterns directs our selection of structural shapes, and the most appropriate type of construction material. In our selection of materials, it is essential to understand all construction materials have flaws, or micro-cracks, which reduce the capacity of the material, especially when subjected to tensions. Because of material defects, many construction materials perform significantly better when subjected to compressive forces. Structures are also more efficient if bending moments are eliminated. Bending stresses produce high peak stresses at each face of the member, and therefore substantially more material is required to resist bending. The shape of the structure also has a profound effect on stress levels. Stress may be reduced dramatically by simply changing the shape. Catenary, triangular and linear shapes are the fundamental structural forms to achieve optimal stress flow. If the natural flow of stress matches the shape of the structures, the most optimal shape is determined.

Keywords: Shell structures, structural optimization, Stress flow, Construction materials, catenary shapes

Procedia PDF Downloads 20

Authors: Christina Peristeri, Tobias Berg, Domenico Caridi, Paul Hutcheson, Robert Winstanley

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In recent years the demand for rapid innovations in the automotive industry has led to the need for accelerated simulation procedures while retaining a detailed representation of the simulated phenomena. The project’s aim is to create a fast transient workflow for external aerodynamic CFD simulations of road vehicles. The geometry used was the SAE Notchback Closed Cooling DrivAer model, and the simulation results were compared with data from wind tunnel tests. The meshes generated for this study were of two types. One was a mix of polyhedral cells near the surface and hexahedral cells away from the surface. The other was an octree hex mesh with a rapid method of fitting to the surface. Three different grid refinement levels were used for each mesh type, with the biggest total cell count for the octree mesh being close to 1 billion. A series of steady-state solutions were obtained on three different grid levels using a pseudo-transient coupled solver and a k-omega-based RANS turbulence model. A mesh-independent solution was found in all cases with a medium level of refinement with 200 million cells. Stress-Blended Eddy Simulation (SBES) was chosen for the transient simulations, which uses a shielding function to explicitly switch between RANS and LES mode. A converged pseudo-transient steady-state solution was used to initialize the transient SBES run that was set up with the SIMPLEC pressure-velocity coupling scheme to reach the fastest solution (on both CPU & GPU solvers). An important part of this project was the use of FLUENT’s Multi-GPU solver. Tesla A100 GPU has been shown to be 8x faster than an Intel 48-core Sky Lake CPU system, leading to significant simulation speed-up compared to the traditional CPU solver. The current study used 4 Tesla A100 GPUs and 192 CPU cores. The combination of rapid octree meshing and GPU computing shows significant promise in reducing time and hardware costs for industrial strength aerodynamic simulations.

Keywords: CFD, DrivAer, LES, Multi-GPU solver, octree mesh, RANS

Procedia PDF Downloads 105

Authors: Tsung Chin Wu, Yu Chen Tsai, Rhay Hung Weng, Weir Sen Lin

Abstract:

In recent years, nursing staff’s lower job satisfaction has led to higher turnover rates, and high turnover rates not only cause medical institution costs to increase but also the quality of medical care to decrease. From the perspective of internal marketing, institution staffs are internal customers, and institutions should focus and meet the needs of staff, so that staff will strive to meet the needs of external customers and provide them with the required care. However, few previous studies have investigated the impact of internal staff satisfaction on external customers. Therefore, this study aimed to conduct job satisfaction surveys on internal staff to investigate the relationship between job satisfaction and quality of medical care through statistical analysis of the study results. The related study results may serve as a reference for healthcare managers. This study was conducted using a questionnaire and the subjects were nursing staff from four hospitals. A total of 600 questionnaires were distributed and 577 valid questionnaires were returned with a response rate of 96.1%. After collecting the data, the reliability and validity of the study variables were confirmed by confirmatory factor analysis. The impact of internal marketing and job satisfaction on turnover intention of nursing staff was analyzed using descriptive analysis, one-way ANOVA, Pearson correlation analysis and multiple regression analysis. The study results showed that there was a significant difference between nursing staff’s job title and ‘professional participation’ and ‘shifts’. There was a significant difference between salary and ‘shifts’ and ‘turnover intention’, as well as between marriage and ‘remuneration’ and ‘turnover intention’. A significant difference was found between professional advancement and ‘professional growth’ and ‘type of leave’, as well as between division of service and ‘shifts’ and ‘turnover intention’. Pearson correlation analysis revealed a significant negative correlation between turnover intention and ‘internal marketing’, ‘interaction’, ‘professional participation’, ‘grasp of environment’, ‘remuneration’ and ‘shifts’, meaning that the higher the satisfaction, the lower the turnover intention. It is recommended that hospitals establish a comprehensive internal marketing mechanism to enhance staff satisfaction and in turn, reduce intention to resign, and the key to increasing job satisfaction is by establishing effective methods of internal communication.

Keywords: internal marketing, job satisfaction, turnover intention, nursing staff

Procedia PDF Downloads 181

Authors: Thomas Lauer

Abstract:

The paper aims to give an overview of change management research by using bibliometric methodology. Based on research papers of the last decade, which are listed on Research Gate, a multidimensional categorization is done. Considering categories like topic (e.g., success factors), industry, or research methodology, the development of the discipline is traced and, in a second step, confronted with external developments of the business environment, such as climate change, gen Z or COVID, to name a few. Based on these findings, a final evaluation concerning the thematical fit of previous research topics is also made, as well as a preview of likely future trends in change management sciences.

Keywords: change management, bibliometrics, scientific trends, research topics

Procedia PDF Downloads 51

Authors: Mustafa Tufekci, Caner Guven

Abstract:

In Automotive Industry, sliding door systems that are also used as body closures, are safety members. Extreme product tests are realized to prevent failures in a design process, but these tests realized experimentally result in high costs. Finite element analysis is an effective tool used for the design process. These analyses are used before production of a prototype for validation of design according to customer requirement. In result of this, the substantial amount of time and cost is saved. Finite element model is created for geometries that are designed in 3D CAD programs. Different element types as bar, shell and solid, can be used for creating mesh model. The cheaper model can be created by the selection of element type, but combination of element type that was used in model, number and geometry of element and degrees of freedom affects the analysis result. Sliding door system is a good example which used these methods for this study. Structural analysis was realized for sliding door mechanism by using FE models. As well, physical tests that have same boundary conditions with FE models were realized. Comparison study for these element types, were done regarding test and analyses results then the optimum combination was achieved.

Keywords: finite element analysis, sliding door mechanism, element type, structural analysis

Procedia PDF Downloads 316

Authors: Ofonime Ogba, Augustine Akpan

Abstract:

Objectives and Goals: The study was aimed at determining pathogenic microbial carriage on the external body parts of Camponotus consobrinus which is also known as the banded sugar ant because of its liking for sugar and sweet food. The level of pathogenic microbial carriage of Camponotus consobrinus in association to the environment in which they have been collected is not known. Methods: The ants were purposively collected from four locations including the kitchens, bedroom of various homes, food shops, and bakeries. The sample collection took place within the hours of 6:30 pm to 11:00 pm. The ants were trapped in transparent plastic containers of which sugar, pineapple peels, sugar cane and soft drinks were used as bait. The ants were removed with a sterile spatula and put in 10mls of peptone water in sterile universal bottles. The containers were vigorously shaken to wash the external surface of the ant. It was left overnight and transported to the Microbiology Laboratory, University of Calabar Teaching Hospital for analysis. The overnight peptone broths were inoculated on Chocolate agar, Blood agar, Cystine Lactose Electrolyte-Deficient agar (CLED) and Sabouraud dextrose agar. Incubation was done aerobically and in a carbon dioxide jar for 24 to 48 hours at 37°C. Isolates were identified based on colonial characteristics, Gram staining, and biochemical tests. Results: Out of the 250 Camponotus consobrinus caught for the study, 90(36.0%) were caught in the kitchen, 75(30.0%) in the bedrooms 40(16.0%) in the bakery while 45(18.0%) were caught in the shops. A total of 82.0% prevalence of different microbial isolates was associated with the ants. The kitchen had the highest number of isolates 75(36.6%) followed by the bedroom 55(26.8%) while the bakery recorded the lowest number of isolates 35(17.1%). The profile of micro-organisms associated with Camponotus consobrinus was Escherichia coli 73(30.0%), Morganella morganii 45(18.0%), Candida species 25(10.0%), Serratia marcescens 10(4.0%) and Citrobacter freundii 10(4.0%). Conclusion: Most of the Camponotus consobrinus examined in the four locations harboured potential pathogens. The presence of ants in homes and shops can facilitate the propagation and spread of pathogenic microorganisms. Therefore, the development of basic preventive measures and the control of ants must be taken seriously.

Keywords: Camponotus consobrinus, potential pathogens, microbial isolates, spread

Procedia PDF Downloads 154

Authors: Igor B. Sivaev

Abstract:

Design of molecular machines is an extraordinary growing and very important area of research that it was recognized by awarding Sauvage, Stoddart and Feringa the Nobel Prize in Chemistry in 2016 'for the design and synthesis of molecular machines'. Based on the type of motion being performed, molecular machines can be divided into two main types: molecular motors and molecular switches. Molecular switches are molecules or supramolecular complexes having bistability, i.e., the ability to exist in two or more stable forms, among which may be reversible transitions under external influence (heating, lighting, changing the medium acidity, the action of chemicals, exposure to magnetic or electric field). Molecular switches are the main structural element of any molecular electronics devices. Therefore, the design and the study of molecules and supramolecular systems capable of performing mechanical movement is an important and urgent problem of modern chemistry. There is growing interest in molecular switches and other devices of molecular electronics based on transition metal complexes; therefore choice of suitable stable organometallic unit is of great importance. An example of such unit is bis(dicarbollide) complexes of transition metals [3,3’-M(1,2-C₂B₉H₁₁)₂]ⁿ⁻. The control on the ligand rotation in such complexes can be reached by introducing substituents which could provide stabilization of certain rotamers due to specific interactions between the ligands, on the one hand, and which can participate as Lewis bases in complex formation with external metals resulting in a change in the rotation angle of the ligands, on the other hand. A series of isomeric methyl sulfide derivatives of cobalt bis(dicarbollide) complexes containing methyl sulfide substituents at boron atoms in different positions of the pentagonal face of the dicarbollide ligands [8,8’-(MeS)₂-3,3’-Co(1,2-C₂B₉H₁₀)₂]⁻, rac-[4,4’-(MeS)₂-3,3’-Co(1,2-C₂B₉H₁₀)₂]⁻ and meso-[4,7’-(MeS)₂-3,3’-Co(1,2-C₂B₉H₁₀)₂]⁻ were synthesized by the reaction of CoCl₂ with the corresponding methyl sulfide carborane derivatives [10-MeS-7,8-C₂B₉H₁₁)₂]⁻ and [10-MeS-7,8-C₂B₉H₁₁)₂]⁻. In the case of asymmetrically substituted cobalt bis(dicarbollide) complexes the corresponding rac- and meso-isomers were successfully separated by column chromatography as the tetrabutylammonium salts. The compounds obtained were studied by the methods of ¹H, ¹³C, and ¹¹B NMR spectroscopy, single crystal X-ray diffraction, cyclic voltammetry, controlled potential coulometry and quantum chemical calculations. It was found that in the solid state, the transoid- and gauche-conformations of the 8,8’- and 4,4’-isomers are stabilized by four intramolecular CH···S(Me)B hydrogen bonds each one (2.683-2.712 Å and 2.709-2.752 Å, respectively), whereas gauche-conformation of the 4,7’-isomer is stabilized by two intramolecular CH···S hydrogen bonds (2.699-2.711 Å). The existence of the intramolecular CH·S(Me)B hydrogen bonding in solutions was supported by the 1H NMR spectroscopy. These data are in a good agreement with results of the quantum chemical calculations. The corresponding iron and nickel complexes were synthesized as well. The reaction of the methyl sulfide derivatives of cobalt bis(dicarbollide) with various labile transition metal complexes results in rupture of intramolecular hydrogen bonds and complexation of the methyl sulfide groups with external metal. This results in stabilization of other rotational conformation of cobalt bis(dicarbollide) and can be used in design of molecular switches. This work was supported by the Russian Science Foundation (16-13-10331).

Keywords: molecular switches, NMR spectroscopy, single crystal X-ray diffraction, transition metal bis(dicarbollide) complexes, quantum chemical calculations

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Authors: Enayatollah Yazdani

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In the post-Cold War era, the world is facing a new emerging global order with the rise of multiple actors in the international arena. China, as a rising global power, has great leverage in internal relations. In particular, during the last two decades, China has rapidly transformed its economy into a global leader in advanced technologies. As a rising power and as one of the two major founding members of the Shanghai Cooperation Organization (SCO), China has tried to use this regional organization, which has the potential to become an important political and security organization of the major states located in the vast Eurasian landmass, for its “go global” strategy. In fact, for Beijing, the SCO represents a new and unique cooperation model, reflecting its vision of a multipolar world order. China has used the SCO umbrella as a multilateral platform to address external threats posed by non-state actors on its vulnerable western border; to gain a strong economic and political foothold in Central Asia without putting the Sino-Russian strategic partnership at risk; and to enhance its energy security through large-scale infrastructure investment in, and trade with, the Central Asian member states. In other words, the SCO is one of the successful outcomes of Chines foreign policy in the post-Cold War era. The expansion of multilateral ties all over the world by dint of pursuing institutional strategies as SCO identifies China as a more constructive power. SCO became a new model of cooperation that was formed on the remains of collapsed Soviet system and predetermined China's geopolitical role in the region. As the fast developing effective regional mechanism, SCO now has more of an external impact on the international system and forms a new type of interaction for promoting China's grand strategy of 'peaceful rise.' This paper aims to answer this major question: How the Chinese government has manipulated the SCO for its foreign policy and global and regional influence? To answer this question, the main discussion is that with regard to the SCO capabilities and politico-economic potential, this organization has been used by China as a platform to expand influence beyond its borders.

Keywords: China, the Shanghai Cooperation Organization (SCO), Central Asia, global policy, foreign policy

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Authors: D. S. Fardhyanti, M. Megawati, H. Prasetiawan, U. Mediaty

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Currently, fossil fuel is supplying most of world’s energy resources. However, fossil fuel resources are depleted rapidly and require an alternative energy to overcome the increasing of energy demands. Bio-oil is one of a promising alternative renewable energy resources which is converted from biomass through pyrolysis or fast pyrolysis process. Bio-oil is a dark liquid fuel, has a smelling smoke and usually obtained from sugar cane, wood, coconut shell and any other biomass. Sugar cane content analysis showed that the content of oligosaccharide, hemicellulose, cellulose and lignin was 16.69%, 25.66%, 51.27% and 6.38% respectively. Sugar cane is a potential sources for bio-oil production shown by its high content of cellulose. In this study, production of bio-oil from sugar cane bagasse was investigated via fast pyrolysis reactor. Fast pyrolysis was carried out at 500 °C with a heating rate of 10 °C and 1 hour holding time at pyrolysis temperature. Physical properties and chemical composition of bio-oil were analyzed. The viscosity, density, calorific value and molecular weight of produced bio-oil was 3.12 cp, 2.78 g/cm3, 11,048.44 cals/g, and 222.67 respectively. The Bio-oil chemical composition was investigated using GC-MS. Percentage value of furfural, phenol, 3-methyl 1,2-cyclopentanedione, 5-methyl-3-methylene 5-hexen-2-one, 4-methyl phenol, 4-ethyl phenol, 1,2-benzenediol, and 2,6-dimethoxy phenol was 20.76%, 16.42%, 10.86%, 7.54%, 7.05%, 7.72%, 5.27% and 6.79% respectively.

Keywords: bio-oil, pyrolysis, bagasse, sugar cane, gas chromatography-mass spectroscopy

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Authors: Richa Dhingra, Monika, Manav Malhotra, Tilak Raj Bhardwaj, Neelima Dhingra

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5-Alpha-reductases (5AR), a membrane bound, NADPH dependent enzyme and convert male hormone testosterone (T) into more potent androgen dihydrotestosterone (DHT). DHT is the required for the development and function of male sex organs, but its overproduction has been found to be associated with physiological conditions like Benign Prostatic Hyperplasia (BPH). Thus the inhibition of 5ARs could be a key target for the treatment of BPH. In present study, 2D and 3D Quantitative Structure Activity Relationship (QSAR) pharmacophore models have been generated for 5AR based on known inhibitory concentration (IC₅₀) values with extensive validations. The four featured 2D pharmacophore based PLS model correlated the topological interactions (–OH group connected with one single bond) (SsOHE-index); semi-empirical (Quadrupole2) and physicochemical descriptors (Mol. wt, Bromines Count, Chlorines Count) with 5AR inhibitory activity, and has the highest correlation coefficient (r² = 0.98, q² =0.84; F = 57.87, pred r² = 0.88). Internal and external validation was carried out using test and proposed set of compounds. The contribution plot of electrostatic field effects and steric interactions generated by 3D-QSAR showed interesting results in terms of internal and external predictability. The well validated 2D Partial Least Squares (PLS) and 3D k-nearest neighbour (kNN) models were used to search novel 5AR inhibitors with different chemical scaffold. To gain more insights into the molecular mechanism of action of these steroidal derivatives, molecular docking and in silico absorption, distribution, metabolism, and excretion (ADME) studies were also performed. Studies have revealed the hydrophobic and hydrogen bonding of the ligand with residues Alanine (ALA) 63A, Threonine (THR) 60A, and Arginine (ARG) 456A of 4AT0 protein at the hinge region. The results of QSAR, molecular docking, in silico ADME studies provide guideline and mechanistic scope for the identification of more potent 5-Alpha-reductase inhibitors (5ARI).

Keywords: 5α-reductase inhibitor, benign prostatic hyperplasia, ligands, molecular docking, QSAR

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Authors: Yulu Zhang, Atushi Teramoto, Taka-Aki Ohkubo

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In this study, the effect of expansive additives on autogenous shrinkage and delayed expansion of ultra-high strength mortar was explored. The specimens made for the study were composed of ultra-high strength mortar, which was mixed with ettringite-lime composite type expansive additive. Two series of experiments were conducted with the specimens. The experimental results confirmed that the autogenous shrinkage of specimens was effectively decreased by increasing the proportion of the expansive additive. On the other hand, for the specimens, which had 7% expansive additive, and were cured for seven days at a constant temperature of 20°C, and then cured for a long time in either in an underwater, moist (Relative humidity: 100%) or dry air (Relative humidity: 60%) environment, excessively large expansion strain occurred. Specifically, typical turtle shell-like swelling expansion cracks were confirmed in the specimens that underwent long-term curing in an underwater and moist environment. According to the result of hydration analysis, the formation of expansive substances, calcium hydroxide and alumina, ferric oxide, tri-sulfate contribute to the occurrence of delayed expansion.

Keywords: ultra-high strength mortar, expansive additive, autogenous shrinkage, delayed expansion

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Authors: G. Massaad, E. Roziere, A. Loukili, L. Izoret

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Based on the monitoring of mass, hydrostatic weighing, and the amount of leached OH- we deduced the nature of leached and precipitated minerals, the amount of lost aggregates and the evolution of porosity and cracking during the sulphate attack. Using these information, we are able to draw the volume / mass changes brought by mineralogical variations and cracking of the cement matrix. Then we defined a new performance indicator, the averaged density, capable to resume along the test of sulphate attack the occurred physicochemical variation occurred in the cementitious matrix and then highlight.

Keywords: monitoring strategy, performance indicator, sulphate attack, mechanism of degradation

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Authors: P. R. Chauhan, S. K. Tyagi

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Adsorption refrigeration technology offers a sustainable and energy-efficient cooling alternative over traditional refrigeration technologies for meeting the fast-growing cooling demands. With its ability to utilize natural refrigerants, low-grade heat sources, and modular configurations, it has the potential to revolutionize the cooling industry. Despite these benefits, the commercial viability of this technology is hampered by several fundamental limiting constraints, including its large size, low uptake capacity, and poor performance as a result of deficient heat and mass transfer characteristics. The primary cause of adequate heat and mass transfer characteristics and magnitude of exergy loss in various real processes of adsorption cooling system can be assessed by the entropy generation rate analysis, i. e. Second law of Thermodynamics. Therefore, this article presents the second law of thermodynamic-based investigation in terms of entropy generation rate (EGR) to identify the energy losses in various processes of the HPCC-based adsorption system using MATLAB R2021b software. The adsorption technology-based cooling system consists of two beds made up of silica gel and arranged in a single stage, while the water is employed as a refrigerant, coolant, and hot fluid. The variation in process-wise EGR is examined corresponding to cycle time, and a comparative analysis is also presented. Moreover, the EGR is also evaluated in the external units, such as the heat source and heat sink unit used for regeneration and heat dump, respectively. The research findings revealed that the combination of adsorber and desorber, which operates across heat reservoirs with a higher temperature gradient, shares more than half of the total amount of EGR. Moreover, the EGR caused by the heat transfer process is determined to be the highest, followed by a heat sink, heat source, and mass transfer, respectively. in case of heat transfer process, the operation of the valve is determined to be responsible for more than half (54.9%) of the overall EGR during the heat transfer. However, the combined contribution of the external units, such as the source (18.03%) and sink (21.55%), to the total EGR, is 35.59%. The analysis and findings of the present research are expected to pinpoint the source of the energy waste in HPCC based adsorption cooling systems.

Keywords: adsorption cooling cycle, heat transfer, mass transfer, entropy generation, silica gel-water

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Authors: Mansour Mohieddin Ghomshei, Reza Shahi

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Laminated composite tubes with adhesively bonded joints are widely used in aerospace and automotive industries as well as oil and gas industries. In this research, adhesively tubular single lap joints subjected to torsional and hygrothermal loadings are studied using the differential quadrature method (DQM). The analysis is based on the classical shell theory. At first, an approximate closed form solution is developed by omitting the lateral deflections in the connecting tubes. Using the analytical model, the circumferential displacements in tubes and the shear stresses in the interfacing adhesive layer are determined. Then, a numerical formulation is presented using DQM in which the lateral deflections are taken into account. By using the DQM formulation, the circumferential and radial displacements in tubes as well as shear and peel stresses in the adhesive layer are calculated. Results obtained from the proposed DQM solutions are compared well with those of the approximate analytical model and those of some published references. Finally using the DQM model, parametric studies are carried out to investigate the influence of various parameters such as adhesive layer thickness, torsional loading, overlap length, tubes radii, relative humidity, and temperature.

Keywords: adhesively bonded joint, differential quadrature method (DQM), hygrothermal, laminated composite tube

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Authors: Abdul Qadir Jangda, Khadija Mariam, Usman Ahmed, Sharib Ahmed

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The Gafchromic EBT3 film has the characteristic of high spatial resolution, weak energy dependence and near tissue equivalence which makes them viable to be used for in-vivo dosimetry in External Beam and Brachytherapy applications. The aim of this study is to assess the smallest film dimension that may be feasible for the use in in-vivo dosimetry. To evaluate the viability, the film sizes from 3 x 3 mm to 20 x 20 mm were calibrated with 6 MV Photon and 6 MeV electron beams. The Gafchromic EBT3 (Lot no. A05151201, Make: ISP) film was cut into five different sizes in order to establish the relationship between absorbed dose vs. film dimensions. The film dimension were 3 x 3, 5 x 5, 10 x 10, 15 x 15, and 20 x 20 mm. The films were irradiated on Varian Clinac® 2100C linear accelerator for dose range from 0 to 1000 cGy using PTW solid water phantom. The irradiation was performed as per clinical absolute dose rate calibratin setup, i.e. 100 cm SAD, 5.0 cm depth and field size of 10x10 cm2 and 100 cm SSD, 1.4 cm depth and 15x15 cm2 applicator for photon and electron respectively. The irradiated films were scanned with the landscape orientation and a post development time of 48 hours (minimum). Film scanning accomplished using Epson Expression 10000 XL Flatbed Scanner and quantitative analysis carried out with ImageJ freeware software. Results show that the dose variation with different film dimension ranging from 3 x 3 mm to 20 x 20 mm is very minimal with a maximum standard deviation of 0.0058 in Optical Density for a dose level of 3000 cGy and the the standard deviation increases with the increase in dose level. So the precaution must be taken while using the small dimension films for higher doses. Analysis shows that there is insignificant variation in the absorbed dose with a change in film dimension of EBT3 film. Study concludes that the film dimension upto 3 x 3 mm can safely be used up to a dose level of 3000 cGy without the need of recalibration for particular dimension in use for dosimetric application. However, for higher dose levels, one may need to calibrate the films for a particular dimension in use for higher accuracy. It was also noticed that the crystalline structure of the film got damage at the edges while cutting the film, which can contribute to the wrong dose if the region of interest includes the damage area of the film

Keywords: external beam radiotherapy, film calibration, film dosimetery, in-vivo dosimetery

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Authors: Mateusz Hermyt, Pawel Kaczmarek, Weronika Rupik

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The egg tooth is a crucial structure during hatching of lizards and snakes. In contrast to birds, turtles, crocodiles, and monotremes, egg tooth of squamate reptiles is a true tooth sharing common features of structure and development with all the other teeth of vertebrates. The egg tooth; however, due to its function, exhibits structural differences in relation to regular teeth. External morphology seems to be important in the context of phylogenetic relationships within Squamata but up to date, there is scarce information concerning structure and development of the egg tooth at the submicroscopical level. In presented studies detailed analysis of the egg tooth development in grass snake has been performed with the usage of light (including fluorescent), transmission and scanning electron microscopy. Grass snake embryo’s heads have been used in our studies. Grass snake is common snake species occurring in most of Europe including Poland. The grass snake is characterized by the presence of single unpaired egg tooth (as in most squamates) in contrast to geckos and dibamids possessing paired egg teeth. Studies show changes occurring on the external morphology, tissue and cellular levels of differentiating egg tooth. The egg tooth during its development changes its curvature. Initially, faces directly downward and in the course of its differentiation, it gradually changes to rostro-ventral orientation. Additionally, it forms conical dentinal protrusions on the sides. Histological analysis showed that egg tooth development occurs in similar steps in relation to regular teeth. It undergoes initiation, bud, cap and bell morphological stages. Analyses focused on describing morphological changes in hard tissues (mainly dentin and predentin) of egg tooth and in cells which enamel organ consists of. It included: outer enamel epithelium, stratum intermedium, inner enamel epithelium, odontoblasts, and cells of dental pulp. All specimens used in the study were captured according to the Polish regulations concerning the protection of wild species. Permission was granted by the Local Ethics Commission in Katowice (41/2010; 87/2015) and the Regional Directorate for Environmental Protection in Katowice (WPN.6401.257.2015.DC).

Keywords: hatching, organogenesis, reptile, Squamata

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Authors: Mohammad Umar Azizi, Tetsuya Ando

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This study investigates the transformation of the traditional landscape of Kabul Old City through an examination of five case study areas. Based on physical observation, three types of houses are found: traditional, mixed and modern. Firstly, characteristics of the houses are described according to construction materials and the number of stories. Secondly, internal and external factors are considered in order to implement a conservation plan. Finally, an adaptive conservation plan is suggested to protect the traditional landscape of Kabul Old City.

Keywords: conservation, district 1, Kabul Old City, landscape, transformation, traditional houses

Procedia PDF Downloads 208