Search results for: two small parameters

Authors: Kathryn L. Duncan, Charles A. Kuntz, Alessandra C. Santamaria, James O. Simcock

Abstract:

Access to megavoltage radiation therapy for small animals is limited in many locations around the world. This can preclude the use of palliative radiation therapy for the treatment of appendicular osteosarcoma in dogs. The objective of this study was to retrospectively assess the adverse effects and survival times of dogs with appendicular osteosarcoma that were treated with hypofractionated orthovoltage radiation therapy and adjunctive carboplatin chemotherapy administered via a single subcutaneous infusion. Medical records were reviewed retrospectively to identify client-owned dogs with spontaneously occurring appendicular osteosarcoma that was treated with palliative orthovoltage radiation therapy and a single subcutaneous infusion of carboplatin. Data recorded included signalment, tumour location, results of diagnostic imaging, haematologic and serum biochemical analyses, adverse effects of radiation therapy and chemotherapy, and survival times. Kaplan-Meier survival analysis was performed, and log-rank analysis was used to determine the impact of specific patient variables on survival time. Twenty-three dogs were identified that met the inclusion criteria. Median survival time for dogs was 182 days. Eleven dogs had adverse haematologic effects, 3 had adverse gastrointestinal effects, 6 had adverse effects at the radiation site and 7 developed infections at the carboplatin infusion site. No statistically significant differences were identified in survival times based on sex, tumour location, development of infection, or pretreatment serum alkaline phosphatase. Median survival time and incidence of adverse effects were comparable to those previously reported in dogs undergoing palliative radiation therapy with megavoltage or cobalt radiation sources and conventional intravenous carboplatin chemotherapy. The use of orthovoltage palliative radiation therapy may be a reasonable alternative to megavoltage radiation in locations where access is limited.

Keywords: radiotherapy, veterinary oncology, chemotherapy, osteosarcoma

Procedia PDF Downloads 73

Authors: Amine.Harbia, Hicham. Moutaabbidb, Yann. Le Godecb, Said. Benmokhtara, Mouhammed. Moutaabbida

Abstract:

This study explores the structural and magnetic characteristics of newly synthesized double perovskite oxides, La₂NiₓCo1-xMnO₆, with x ranging from 0.2 to 0.8. Utilizing X-ray powder diffraction and SQUID magnetometry, we analyzed the compounds that consistently exhibit a monoclinic structure with the P21/n space group at ambient temperature. it findings reveal that as Ni2+ is progressively substituted by Co2+, there is a corresponding decrease in cell parameters, attributable to the smaller ionic radius of Ni2+ (0.69 Å) compared to Co2+ (0.74 Å). The crystal structure features octahedrally coordinated (Co/Ni)2+ and Mn4+ cations with oxygen, forming (Co/Ni)O6 and MnO6 octahedra linked via oxygen atoms along different crystallographic axes. Magnetic characterization conducted over a temperature range of 2 to 300 K in both DC and AC magnetic fields, showed a predominant paramagnetic to ferromagnetic transition between 232 K and 260 K, with the Curie temperature notably increasing with higher x values. Samples with x=0.2, 0.25, and 0.5 exhibited a secondary PM-FM transition between 200 K and 208 K. Cation ordering was quantitatively assessed, indicating a higher ordering in Ni2+-rich samples (x=0.75 and 0.8) at over 96%, whereas the sample with x=0.25 showed minimal ordering. Furthermore, the out-of-phase component of the AC susceptibility displayed frequency-dependent transitions between 65 K and 110 K, suggesting the presence of superparamagnetic domains across all samples.

Keywords: double perovskite oxides, magnetic transitions, cation ordering, squid magnetometry

Procedia PDF Downloads 60

Authors: Denise Schrama, Claudia Raposo, Pedro Rodrigues

Abstract:

Background: Food allergies are conducted by a hypersensitive response of the immune system. These allergies are a global concern for the public health. Consumption of fish is increasing worldwide as it is a healthy meat with high nutritional value. Unfortunately, fish can cause adverse immune-mediate reactions, affecting part of the population with higher incidence in children. β-parvalbumin, a small, highly conserved stable, calcium or magnesium binding muscle protein is the main fish allergen. In fish-allergic patients, cross-reactivity between different fish species exist due to recognition of highly identical protein regions. Enolases, aldolases, or fish gelatin are other identified fish allergens in some fish species. With no available cure for fish allergies, clinical management is only based on an avoidance diet aiming at the total exclusion of offending food. Methods: Mediterranean fish (S. aurata and D. labrax) were fed specifically designed diets, enriched in components that target the expression or inactivation of parvalbumin (creatine and EDTA, respectively). After 90 days fish were sampled and biological tissues were excised. Proteomics was used to access fish allergens characterization and expression in muscle while IgE assays to confirm the lower allergenic potential are conducted in patients with history of fish allergies. Fish welfare and quality of flesh were established with biochemical, texture and sensorial analysis. Results: Fish welfare shows no major impact between diets. In case of creatine supplementation in D. labrax proteomic analysis show a slight decrease in parvalbumin expression. No accumulation of this compound was found in muscle. For EDTA supplementation in S. aurata IgE assay show a slight decrease in allergenicity when using sera of fish allergic patients. Conclusion: Supplementation with these two compounds seems to change slightly the allergenicity of the two mean Mediterranean species.

Keywords: fish allergies, fish nutrition, proteomics, aquaculture

Procedia PDF Downloads 156

Authors: Mehmet Nefes, Selman Demirel, Hasan H. Ertok, Cenk Sen

Abstract:

A typical reliability engineering problem regarding communication satellites has been considered to determine redundancy allocation scheme of power amplifiers within payload transponder module, whose dominant function is to amplify power levels of the received signals from the Earth, through maximizing reliability against mass, power, and other technical limitations. Adding each redundant power amplifier component increases not only reliability but also hardware, testing, and launch cost of a satellite. This study investigates a multi-objective approach used in order to solve Redundancy Allocation Problem (RAP) for a communication satellite payload transponder, focusing on design cost due to redundancy and reliability factors. The main purpose is to find the optimum power amplifier redundancy configuration satisfying reliability and capacity thresholds simultaneously instead of analyzing respectively or independently. A mathematical model and calculation approach are instituted including objective function definitions, and then, the problem is solved analytically with different input parameters in MATLAB environment. Example results showed that payload capacity and failure rate of power amplifiers have remarkable effects on the solution and also processing time.

Keywords: communication satellite payload, multi-objective optimization, redundancy allocation problem, reliability, transponder

Procedia PDF Downloads 261

Authors: Reza Ziaie Moayed, Ehsan Azini

Abstract:

Jet grouting (JG) is one of the methods of improving and increasing the strength and bearing of soil in which the high pressure water or grout is injected through the nozzles into the soil. During this process, a part of the soil and grout particles comes out of the drill borehole, and the other part is mixed up with the grout in place, as a result of this process, a mass of modified soil is created. The purpose of this method is to change the soil into a mixture of soil and cement, commonly known as "soil-cement". In this paper, first, the principles of high pressure injection and then the effective parameters in the JG method are described. Then, the tests on the samples taken from the columns formed from the excavation around the soil-cement columns, as well as the static loading test on the created column, are discussed. In the other part of this paper, the soil behavior models for numerical modeling in PLAXIS software are mentioned. The purpose of this paper is to evaluate the results of numerical modeling based on in-situ static loading tests. The results indicate an acceptable agreement between the results of the tests mentioned and the modeling results. Also, modeling with this software as an appropriate option for technical feasibility can be used to soil improvement using JG.

Keywords: jet grouting column, soil improvement, numerical modeling, in-situ loading test

Procedia PDF Downloads 143

Authors: Doaa M. Atia, Faten H. Fahmy, Ninet M. A. El-Rahman, Hassan T. Dorra

Abstract:

In this paper, the optimum design for renewable energy system powered an aquaculture pond was determined. Hybrid Optimization Model for Electric Renewable (HOMER) software program, which is developed by U.S National Renewable Energy Laboratory (NREL), is used for analyzing the feasibility of the stand-alone and hybrid system in this study. HOMER program determines whether renewable energy resources satisfy hourly electric demand or not. The program calculates energy balance for every 8760 hours in a year to simulate operation of the system. This optimization compares the demand for the electrical energy for each hour of the year with the energy supplied by the system for that hour and calculates the relevant energy flow for each component in the model. The essential principle is to minimize the total system cost while HOMER ensures control of the system. Moreover the feasibility analysis of the energy system is also studied. Wind speed, solar irradiance, interest rate and capacity shortage are the parameters which are taken into consideration. The simulation results indicate that the hybrid system is the best choice in this study, yielding lower net present cost. Thus, it provides higher system performance than PV or wind stand-alone systems.

Keywords: wind stand-alone system, photovoltaic stand-alone system, hybrid system, optimum system sizing, feasibility, cost analysis

Procedia PDF Downloads 340

Authors: H. S. S. Abou El-Mal, H. E. M. Sallam

Abstract:

This paper presents experimental and analytical study on the behavior of repaired and strengthened shear critical RC beams using externally bonded CFRP bi-directional fabrics. The use of CFRP sheets to repair or strengthen RC beams has been repetitively studied and proven feasible. However, the use of combined repair techniques and applying that method to both plain and FRC beams can maximize the shear capacity of RC shear deficient beams. A total of twelve slender beams were tested under four-point bending. The test parameters included CFRP layout, number of layers and fiber direction, injecting cracks before applying repairing sheets, enhancing the flexural capacity to differentiate between shear repair and strengthening techniques, and concrete matrix types. The findings revealed that applying CFRP sheets increased the overall shear capacity, the amount and orientation of wrapping is of prime importance in both repairing and strengthening, CFRP wrapping could change the failure mode from shear to flexural shear, the use of crack injection combined to CFRP wrapping further improved the shear capacity while, applying the previous method to FRC beams enhanced both shear capacity and failure ductility. Acceptable agreement was found between predicted shear capacities using the Canadian code and the experimental results of the current study.

Keywords: CFRP, FRC, repair, shear strengthening

Procedia PDF Downloads 349

Authors: Assem M. F. Sallam, Ah. El-S. Makled

Abstract:

This paper presents a study on the trajectory of a two stage launch vehicle. The study includes dynamic responses of motion parameters as well as the variation of angles affecting the orientation of the launch vehicle (LV). LV dynamic characteristics including state vector variation with corresponding altitude and velocity for the different LV stages separation, as well as the angle of attack and flight path angles are also discussed. A flight trajectory study for the drop zone of first stage and the jettisoning of fairing are introduced in the mathematical modeling to study their effect. To increase the accuracy of the LV model, atmospheric model is used taking into consideration geographical location and the values of solar flux related to the date and time of launch, accurate atmospheric model leads to enhancement of the calculation of Mach number, which affects the drag force over the LV. The mathematical model is implemented on MATLAB based software (Simulink). The real available experimental data are compared with results obtained from the theoretical computation model. The comparison shows good agreement, which proves the validity of the developed simulation model; the maximum error noticed was generally less than 10%, which is a result that can lead to future works and enhancement to decrease this level of error.

Keywords: launch vehicle modeling, launch vehicle trajectory, mathematical modeling, Matlab- Simulink

Procedia PDF Downloads 277

Authors: Haidy N. Salem, Nada O. Kamel, Shahinaz N. Hassan, Sherif M. Elhefnawy

Abstract:

Aim: to assess the effect of using turmeric powder extract on changes of tooth color with extra-coronal and intra-coronal bleaching methods. Methods: Turmeric powder extract was weighted and mixed with two different hydrogen peroxide concentrations (3% and 6%) to be used as a bleaching agent. Thirty teeth were allocated into three groups (n=10): Group A: Bleaching agent (6%) was applied on the labial surface, Group B: Bleaching agent (3%) was applied inside the pulp chamber and Group C: Extra and intra-coronal bleaching techniques were used (6% and 3% respectively). A standardized access cavity was opened in the palatal surface of each tooth in both Groups B and C. Color parameters were measured using a spectrophotometer. Results: A statistically significant difference in color difference values (∆E*) and enamel brightness (∆L*) was found between Group C and each of Groups A and B. There was no statistically significant difference in (∆E*) and (∆L*) between Group A and Group B. The highest mean value of (∆E*) and (∆L*) was found in Group C, while the least mean value was found in Group B. Conclusion: Bleaching the external and internal tooth structure with low concentrations of hydrogen peroxide solution mixed with turmeric extract has a promising effect in color enhancement.

Keywords: bleaching, hydrogen peroxide, spectrophotometer, turmeric

Procedia PDF Downloads 119

Authors: Yimeng Zhang

Abstract:

Major depressive disorder (MDD) is a prevalent mental health condition with a substantial economic impact and limited treatment options. Acupuncture has gained attention as a promising non-pharmacological intervention for alleviating depressive symptoms. However, its mechanisms and clinical effectiveness remain incompletely understood. This meta-analysis aims to (1) synthesize existing evidence on the mechanisms and clinical effectiveness of acupuncture for depression and (2) compare these findings with pharmacological interventions, providing insights for future research. Evidence from animal models and clinical studies indicates that acupuncture may enhance hippocampal and network neuroplasticity and reduce brain inflammation, potentially alleviating depressive disorders. Clinical studies suggest that acupuncture can effectively relieve primary depression, particularly in milder cases, and is beneficial in managing post-stroke depression, pain-related depression, and postpartum depression, both as a standalone and adjunctive treatment. Notably, combining acupuncture with antidepressant pharmacotherapy appears to enhance treatment outcomes and reduce medication side effects, addressing a critical issue in conventional drug therapy's high dropout rates. This meta-analysis, encompassing 12 studies and 710 participants, draws data from eight digital databases (PubMed, EMBASE, Web of Science, EBSCOhost, CNKI, CBM, Wangfang, and CQVIP) covering the period from 2012 to 2022. Utilizing Stata software 15.0, the meta-analysis employed random-effects and fixed-effects models to assess the distribution of depression in Traditional Chinese Medicine (TCM). The results underscore the substantial evidence supporting acupuncture's beneficial effects on depression. However, the small sample sizes of many clinical trials raise concerns about the generalizability of the findings, indicating a need for further research to validate these outcomes and optimize acupuncture's role in treating depression.

Keywords: Chinese medicine, acupuncture, depression, meta-analysis

Procedia PDF Downloads 35

Authors: Tanwarat Kajsongkram, Saowalux Rotamporn, Sirinat Limbunruang, Sirinan Thubthimthed.

Abstract:

High-Performance Liquid Chromatography (HPLC) method was developed and validated for simultaneous estimation of 6-Gingerol(6G) and 6-Shogaol(6S) in joint pain relief gel containing ginger extract. The chromatographic separation was achieved by using C18 column, 150 x 4.6mm i.d., 5μ Luna, mobile phase containing acetonitrile and water (gradient elution). The flow rate was 1.0 ml/min and the absorbance was monitored at 282 nm. The proposed method was validated in terms of the analytical parameters such as specificity, accuracy, precision, linearity, range, limit of detection (LOD), limit of quantification (LOQ), and determined based on the International Conference on Harmonization (ICH) guidelines. The linearity ranges of 6G and 6S were obtained over 20-60 and 6-18 µg/ml respectively. Good linearity was observed over the above-mentioned range with linear regression equation Y= 11016x- 23778 for 6G and Y = 19276x-19604 for 6S (x is concentration of analytes in μg/ml and Y is peak area). The value of correlation coefficient was found to be 0.9994 for both markers. The limit of detection (LOD) and limit of quantification (LOQ) for 6G were 0.8567 and 2.8555 µg/ml and for 6S were 0.3672 and 1.2238 µg/ml respectively. The recovery range for 6G and 6S were found to be 91.57 to 102.36 % and 84.73 to 92.85 % for all three spiked levels. The RSD values from repeated extractions for 6G and 6S were 3.43 and 3.09% respectively. The validation of developed method on precision, accuracy, specificity, linearity, and range were also performed with well-accepted results.

Keywords: ginger, 6-gingerol, HPLC, 6-shogaol

Procedia PDF Downloads 444

Authors: Neda Azari Dodaran, Hamid Ahmadi

Abstract:

Results of 405 finite element (FE) analyses were used in the present research to study the effect of the joint geometry on the ultimate strength and initial stiffness of tubular K-joints subjected to axial loading at fire-induced elevated temperatures. The FE models were validated against the data available from experimental tests. Structural behavior under different temperatures (200ºC, 400ºC, 500ºC, and 700ºC) was investigated and compared to the behavior at ambient temperature (20ºC). A parametric study was conducted to investigate the effect of dimensionless geometrical parameters (β, γ, θ, and τ) on the ultimate strength and initial stiffness. Afterwards, ultimate strength data extracted from the FE analyses were compared with the values calculated from the equations proposed by available design codes in which the ultimate strength of the joint at elevated temperatures is obtained by replacing the yield stress of the steel at ambient temperature with the corresponding value at elevated temperature. It was indicated that this method may not have acceptable accuracy for K-joints under axial loading. Hence, a design formula was developed, through nonlinear regression analyses, to determine the ultimate strength of K-joints subjected to balanced axial loads at elevated temperatures.

Keywords: axial loading, elevated temperature, parametric equation, static strength, tubular K-joint

Procedia PDF Downloads 149

Authors: G. Kermarrec, J. Hartmann

Abstract:

Spline surfaces are a major representation of freeform surfaces in the computer-aided graphic industry and were recently introduced in the field of geodesy for processing point clouds from terrestrial laser scanner (TLS). The surface fitting consists of approximating a trustworthy mathematical surface to a large numbered 3D point cloud. The standard B-spline surfaces lack of local refinement due to the tensor-product construction. The consequences are oscillating geometry, particularly in the transition from low-to-high curvature parts for scattered point clouds with missing data. More economic alternatives in terms of parameters on how to handle point clouds with a huge amount of observations are the recently introduced T-splines. As long as the partition of unity is guaranteed, their computational complexity is low, and they are flexible. T-splines are implemented in a commercial package called Rhino, a 3D modeler which is widely used in computer aided design to create and animate NURBS objects. We have applied T-splines surface fitting to terrestrial laser scanner point clouds from a bridge under load and a sheet pile wall with noisy observations. We will highlight their potential for modelling details with high trustworthiness, paving the way for further applications in terms of deformation analysis.

Keywords: deformation analysis, surface modelling, terrestrial laser scanner, T-splines

Procedia PDF Downloads 140

Authors: R. Noorani, K. Peerless, J. Mandrell, A. Lopez, R. Dalberto, M. Alzebaq

Abstract:

Rapid prototyping (RP) is an additive manufacturing technology used in industry that works by systematically depositing layers of working material to construct larger, computer-modeled parts. A key challenge associated with this technology is that RP parts often feature undesirable levels of surface roughness for certain applications. To combat this phenomenon, an experimental technique called Design of Experiments (DOE) can be employed during the growth procedure to statistically analyze which RP growth parameters are most influential to part surface roughness. Utilizing DOE to identify such factors is important because it is a technique that can be used to optimize a manufacturing process, which saves time, money, and increases product quality. In this study, a four-factor/two level DOE experiment was performed to investigate the effect of temperature, layer thickness, infill percentage, and infill speed on the surface roughness of RP prototypes. Samples were grown using the sixteen different possible growth combinations associated with a four-factor/two level study, and then the surface roughness data was gathered for each set of factors. After applying DOE statistical analysis to these data, it was determined that layer thickness played the most significant role in the prototype surface roughness.

Keywords: rapid prototyping, surface roughness, design of experiments, statistical analysis, factors and levels

Procedia PDF Downloads 262

Authors: Bachir Kacimi, Fatiha Teklal, Arezki Djebbar

Abstract:

Forming processes induce residual deformations on the reinforcement and sometimes lead to mesoscopic defects, which are more recurrent than macroscopic defects during the manufacture of complex structural parts. This study deals with the influence of the fabric shear and buckles defects, which appear during draping processes of composite, on the impact behavior of a glass fiber reinforced polymer. To achieve this aim, we produced several specimens with different amplitude of deformations (shear) and defects on the fabric using a specific bench. The specimens were manufactured using the contact molding and tested with several impact energies. The results and measurements made on tested specimens were compared to those of the healthy material. The results showed that the buckle defects have a negative effect on elastic parameters and revealed a larger damage with significant out-of-plane mode relatively to the healthy composite material. This effect is the consequence of a local fiber impoverishment and a disorganization of the fibrous network, with a reorientation of the fibers following the out-of-plane buckling of the yarns, in the area where the defects are located. For the material with calibrated shear of the reinforcement, the increased local fiber rate due to the shear deformations and the contribution to stiffness of the transverse yarns led to an increase in mechanical properties.

Keywords: Defects, Forming, Impact, Induced properties, Textiles

Procedia PDF Downloads 140

Authors: A. Hegazy, Ahmed Elsayed, Essam El Shenawy, N. Allam, Hala Handal, K. R. Mahmoud

Abstract:

Highly crystalline, TiO₂ pristine sub-10 nm anatase nanocrystals were fabricated at low temperatures by post hydrothermal treatment of the as-prepared TiO₂ nanoparticles. This treatment resulted in bandgap narrowing and increased photocurrent density value (3.8 mA/cm²) when this material was employed in water splitting systems. The achieved photocurrent values are among the highest reported ones so far for the fabricated nanoparticles at this low temperature. This might be explained by the increased surface defects of the prepared nanoparticles. It resulted in bandgap narrowing that was further investigated using positron annihilation experiments by measuring positron lifetime and Doppler broadening. Besides, homogeneous spherical TiO₂ nanoparticles were synthesized in large diameter and high surface area and the high percentage of (001) facet by sol-gel method using potassium persulfate (K₂S₂O₈) as an oxidizing agent. The fabricated particles exhibited high exposed surface area, high photoactivity and reduced band gap. Enhanced performance for water splitting applications was displayed by formed TiO₂ nanoparticles. Their morphological and structural properties were studied to optimize their synthesis parameters in an attempt to construct more applicable fuel cells in the industry for hydrogen fuel production.

Keywords: positron annihilation, solar energy, TiO2 nanoparticles, water splitting

Procedia PDF Downloads 145

Authors: Axel Mancebo, Ana M. Bada, Angel Casacó, Bárbara González, Avelina León, María E. Arteaga, Consuelo González, Belinda Sánchez, Adriana Carr, Nuris Ledón, Arianna Iglesias

Abstract:

Despite the many preventive and therapeutic modalities aimed at curing cancer, it remains as a serious world health problem. Promising recent developments suggest that cancer immunotherapy may be the next great hope for cancer treatment. EGFRs are receptor tyrosine kinases and it is considered an important therapeutic target related with tumor progression, and several types of molecular therapies, including monoclonal antibodies, small molecules, and vaccines, have been developed to target the HER family of receptors. On the other hand, gangliosides are membrane glycosphingolipids that contain two variants of sialic acid, the N-acetylated (NeuAc) and the N-glycolylated (NeuGc) variant. The high expression of this antigen-specific molecule has been associated with malignant tumor progression and immunosuppressive mechanisms, so ganglioside could be considered as the target for cancer immunotherapy. We have been working for several years in the safety evaluation of cancer vaccines targeting these two systems, the EGF receptor and ganglioside. We presented in this work results of repeated dose toxicity studies performed in Sprague Dawley rats and Cynomolgus monkeys, including clinical observations, body weight and rectal temperature measuring, clinical pathology analysis, gross necropsy and histological examination in rodent studies, and immunological evaluation. Immunizations were capable of inducing mainly inflammatory effects at the injection site, with findings largely attributable to the adjuvants used and probably enhanced by the immunological properties of the antigens. In general, these vaccines were shown to be well tolerated, and these studies in relevant species allow treating cancer patients with tumors during long periods with relative weight safety margin.

Keywords: cancer vaccines, safety, toxicology, rats, non human primates

Procedia PDF Downloads 450

Authors: Lauren C. Porter, Andrew Curtis, Eric Jefferis, Susanne Mitchell

Abstract:

A wealth of research has been generated examining the variation in crime across neighborhoods. However, there is also a striking degree of crime concentration within neighborhoods. A number of studies show that a small percentage of street segments, intersections, or addresses account for a large portion of crime. Not surprisingly, a focus on these crime hot spots can be an effective strategy for reducing community level crime and related ills, such as health problems. However, research is also limited in an important respect. Studies tend to use official data to identify hot spots, such as 911 calls or calls for service. While the use of call data may be more representative of the actual level and distribution of crime than some other official measures (e.g. arrest data), call data still suffer from the 'dark figure of crime.' That is, there is most certainly a degree of error between crimes that occur versus crimes that are reported to the police. In this study, we present an alternative method of identifying crime hot spots, that does not rely on official data. In doing so, we highlight the potential utility of neighborhood-insiders to identify and understand crime dynamics within geographic spaces. Specifically, we use spatial video and geo-narratives to record the crime insights of 36 police, ex-offenders, and residents of a high crime neighborhood in northeast Ohio. Spatial mentions of crime are mapped to identify participant-identified hot spots, and these are juxtaposed with calls for service (CFS) data. While there are bound to be differences between these two sources of data, we find that one location, in particular, a corner store, emerges as a hot spot for all three groups of participants. Yet it does not emerge when we examine CFS data. A closer examination of the space around this corner store and a qualitative analysis of narrative data reveal important clues as to why this store may indeed be a hot spot, but not generate disproportionate calls to the police. In short, our results suggest that researchers who rely solely on official data to study crime hot spots may risk missing some of the most dangerous places.

Keywords: crime, narrative, video, neighborhood

Procedia PDF Downloads 238

Authors: V. Pentland, S. Spilsbury, A. Biswas, M. F. Mottola, S. Paplinskie, M. S. Mitchell

Abstract:

Postpartum depression (PPD) is a form of major depressive disorder that afflicts 10–22% of mothers worldwide. Rising demands for traditional PPD treatment options (e.g., psychiatry), especially in the context of the COVID-19 pandemic, are increasingly difficult to meet. More accessible treatment options (e.g., walking) are needed. The objective of this review is to determine the impact of walking on PPD severity. A structured search of seven electronic databases for randomised controlled trials published between 2000 and July 29, 2021, was completed. Studies were included if walking was the sole or primary aerobic exercise modality. A random-effects meta-analysis was conducted for studies reporting PPD symptoms measured using a clinically validated tool. A simple count of positive/null effect studies was undertaken as part of a narrative summary. Five studies involving 242 participants were included (mean age=~28.9 years; 100% with mild-to-moderate depression). Interventions were 12 (n=4) and 24 (n=1) weeks long. Each assessed PPD severity using the Edinburgh Postnatal Depression Scale (EPDS) and was included in the meta-analysis. The pooled effect estimate suggests that relative to controls, walking yielded clinically significant decreases in mean EPDS scores from baseline to intervention end (pooled MD=-4.01; 95% CI:-7.18 to -0.84, I2=86%). The narrative summary provides preliminary evidence that walking-only, supervised, and group-based interventions, including 90-120+ minutes/week of moderate-intensity walking, may produce greater EPDS reductions. While limited by a relatively small number of included studies, pooled effect estimates suggest walking may help mothers manage PPD. This is the first time walking as a treatment for PPD, an exercise modality that uniquely addresses many barriers faced by mothers has been summarized in a systematic way. Trial registration: PROSPERO (CRD42020197521) on August 16th, 2020

Keywords: postpartum, exercise, depression, walking

Procedia PDF Downloads 204

Authors: M. Moody, R. Mahmoodi, A. R. Zolfaghari, A. Aminottojari

Abstract:

In this study, flow inside the shell side of a shell-and-tube heat exchanger is simulated numerically for laminar and turbulent flows in both steady state and transient mode. Governing equations of fluid flow are discrete using finite volume method and central difference scheme and solved with simple algorithm which is staggered grid by using MATLAB programming language. The heat transfer coefficient is obtained using velocity field from equation Dittus-Bolter. In comparison with, heat exchanger is simulated with ANSYS CFX software and experimental data measured in the THTL test loop. Numerical results obtained from the study show good agreement with experimental data and ANSYS CFX results. In addition, by deliberation the effect of the baffle spacing and the baffle cut on the heat transfer rate for turbulent flow, it is illustrated that the heat transfer rate depends on the baffle spacing and the baffle cut directly. In other word in spied of large turbulence, if these two parameters are not selected properly in the heat exchanger, the heat transfer rate can reduce.

Keywords: shell-and-tube heat exchanger, flow and heat transfer, laminar and turbulence flow, turbulence model, baffle spacing, baffle cut

Procedia PDF Downloads 537

Authors: Mallikarjunachari Gangapuram

Abstract:

Stimuli-responsive hydrogel nanocomposite membranes are gaining significant attention these days due to their potential applications in various engineering fields. For example, sensors, soft actuators, drug delivery, remote controlled therapy, water treatment, shape morphing, and magnetic refrigeration are few advanced applications of hydrogel nanocomposite membranes. In this work, hydrogel nanocomposite membranes are synthesized by embedding nanometer-sized (diameter - 300 nm) Fe₃O₄ magnetic particles into the polyvinyl alcohol (PVA) polymer. To understand the large deformation characteristics of these membranes, a well-known experimental method ball indentation technique is used. Different designing parameters such as membrane thickness, the concentration of magnetic particles and ball diameter on the viscoelastic properties are studied. All the experiments are carried out without and with a static magnetic field. Finite element simulations are carried out to validate the experimental results. It is observed, the creep response decreases and Young’s modulus increases as the thickness and concentration of magnetic particles increases. Image analysis revealed the hydrogel membranes are undergone global deformation for ball diameter 18 mm and local deformation when the diameter decreases from 18 mm to 0.5 mm.

Keywords: ball indentation, hydrogel membranes, nanocomposites, Young's modulus

Procedia PDF Downloads 128

Authors: Ziyad Abunada, Abir Al-tabbaa

Abstract:

The current work is investigating the effectiveness of combined mixed materials mainly modified bentonites and organoclay in treating contaminated groundwater. Sodium bentonite was manufactured with a quaternary amine surfactant, dimethyl ammonium chloride to produce organoclay (OC). Inorgano-organo bentonite (IOB) was produced by intercalating alkylbenzyd-methyl-ammonium chloride surfactant into sodium bentonite and pillared with chlorohydrol pillaring agent. The materials efficiency was tested for both TEX compounds from model-contaminated water and a mixture of organic contaminants found in groundwater samples collected from a contaminated site in the United Kingdom. The sorption data was fitted well to both Langmuir and Freundlich adsorption models reflecting the double sorption model where the correlation coefficient was greater than 0.89 for all materials. The mixed materials showed higher sorptive capacity than individual material with a preference order of X> E> T and a maximum sorptive capacity of 21.8 mg/g was reported for IOB-OC materials for o-xylene. The mixed materials showed at least two times higher affinity towards a mixture of organic contaminants in groundwater samples. Other experimental parameters such as pH and contact time were also investigated. The pseudo-second-order rate equation was able to provide the best description of adsorption kinetics.

Keywords: modified bentobite, groundwater, adsorption, contaminats

Procedia PDF Downloads 225

Authors: Hadjadj Abdechafik, Kious Mecheri, Ameur Aissa

Abstract:

The objective of this study is to develop a process of treatment of the vibratory signals generated during a horizontal high speed milling process without applying any coolant in order to establish a monitoring system able to improve the machining performance. Thus, many tests were carried out on the horizontal high speed centre (PCI Météor 10), in given cutting conditions, by using a milling cutter with only one insert and measured its frontal wear from its new state that is considered as a reference state until a worn state that is considered as unsuitable for the tool to be used. The results obtained show that the first harmonic follow well the evolution of frontal wear, on another hand a wavelet transform is used for signal processing and is found to be useful for observing the evolution of the wavelet approximations through the cutting tool life. The power and the Root Mean Square (RMS) values of the wavelet transformed signal gave the best results and can be used for tool wear estimation. All this features can constitute the suitable indicators for an effective detection of tool wear and then used for the input parameters of an online monitoring system. Although we noted the remarkable influence of the machining cycle on the quality of measurements by the introduction of a bias on the signal, this phenomenon appears in particular in horizontal milling and in the majority of studies is ignored.

Keywords: flank wear, vibration, milling, signal processing, monitoring

Procedia PDF Downloads 598

Authors: Samina Sarwar, Hajra Khalil

Abstract:

Mycoremediation is emerging as a potential approach for eco-friendly and cost-effective remediation of polluted effluents collected from the dyeing unit of the textile industry was examined. This work dealt with the analyses of the bio remedial capability of some potential indigenous six fungal isolates viz., Aspergillus alliaceus, Aspergillus flavus, Aspergillus fumigatus Aspergillus niger, Penicillium sp. and Rhizopus oryzae were identified and selected for studies. All fungal species were known to bring bioremediation, which had been confirmed by measuring the percentage reduction potential in different parameters, i.e., pH, Electrical Conductivity (EC), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Rhizopus oryzae showed the highest reduction in pH, EC, and BOD, while Aspergillus fumigatus showed the highest reduction in TDS and TSS, and COD under the optimal conditions of this study. The biodegradation potential of these fungal species was confirmed, evidenced by excellent evaluation of experimental data to propose Rhizopus oryzae and Aspergillus fumigatus as a cost-effective solution to treat the effluents from the dyeing unit of the textile industry.

Keywords: biological reduction, fungal isolates, micromycetes, mycoremediation

Procedia PDF Downloads 79

Authors: Samina Sarwar, Hajra Khalil

Abstract:

Mycoremediation is emerging as a potential approach for eco-friendly and cost-effective remediation of polluted effluents collected from the dyeing unit of the textile industry was examined. This work dealt with the analyses of the bio remedial capability of some potential indigenous six fungal isolates viz., Aspergillus alliaceus, Aspergillus flavus, Aspergillus fumigatus Aspergillus niger, Penicillium sp. and Rhizopus oryzae were identified and selected for studies. All fungal species were known to bring bioremediation, which had been confirmed by measuring the percentage reduction potential in different parameters, i.e., pH, Electrical Conductivity (EC), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Rhizopus oryzae showed the highest reduction in pH, EC, and BOD, while Aspergillus fumigatus showed the highest reduction in TDS and TSS, and COD under the optimal conditions of this study. The biodegradation potential of these fungal species was confirmed, evidenced by excellent evaluation of experimental data to propose Rhizopus oryzae and Aspergillus fumigatus as a cost-effective solution to treat the effluents from the dyeing unit of the textile industry.

Keywords: biological reduction, fungal isolates, micromycetes, mycoremediation

Procedia PDF Downloads 95

Authors: Doua AlSaad, Ahmed Awaisu, Samah Elsalem, Palli Valapila Abdulrouf, Binny Thomas, Moza AlHail

Abstract:

Background: It has been suggested that pyridoxine has an anti-lactogenic effect. Studies of the efficacy of pyridoxine in suppressing lactation have reported conflicting results. The aim of this review is to evaluate the effectiveness and safety of high-dose pyridoxine in postpartum lactation inhibition. Methods: This systematic review included published trials that compared the efficacy and/or safety of pyridoxine to placebo or to other pharmacological agents for the inhibition of postpartum lactation. We searched PubMed, Embase, ScienceDirect, CINAHL, AMED, the Cochrane library, and the clinical trials registry to identify relevant literature. No limit was imposed on the year of publication of the studies, and the review included studies published until 15 January 2016. Two reviewers independently extracted data and assessed the risk of bias. Results: Seven studies were included, with a total of 1155 women, of which 471 women received pyridoxine. Three studies were randomized controlled trials, while the remaining four studies were non-randomized controlled trials. All of the included studies were relatively small (n = 18 – 482). The studies compared pyridoxine with placebo, bromocriptine, and/or stilboestrol. Pyridoxine was given orally, with a total daily dose of 450 – 600 mg for 5 to 7 days. Two trials (n = 349 participants) indicated that pyridoxine was effective in inhibiting lactation in approximately 95% of the enrolled patients. All other studies failed to demonstrate pyridoxine efficacy through either clinical assessment or prolactin level measurements. Pyridoxine safety was assessed by two trials in which no serious untoward side-effects were reported. Overall, the risk of bias for most of the studies was low to moderate. Conclusion: Current evidence supporting the effectiveness of high dose pyridoxine in the inhibition of postpartum lactation is inconsistent and insufficient. Larger randomized trials are needed to confirm the efficacy of pyridoxine in postpartum lactation inhibition. Acknowledgment: This review received a grant from the Medical Research Center of Hamad Medical Corporation in Qatar (grant number: 15100/15).

Keywords: pyridoxine, safety, effectiveness, lactation inhibition

Procedia PDF Downloads 134

Authors: Nahid Hassanshahi, Ayoub Karimi-Jashni, Nasser Talebbeydokhti

Abstract:

Due to the economic and environmental benefits of producing less waste, the US Environmental Protection Agency (EPA) introduces source reduction as one of the most important means to deal with the problems caused by increased landfills and pollution. Waste reduction involves all waste management methods, including source reduction, recycling, and composting, which reduce waste flow to landfills or other disposal facilities. Source reduction of waste can be studied from two perspectives: avoiding waste production, or reducing per capita waste production, and waste deviation that indicates the reduction of waste transfer to landfills. The present paper has investigated home composting as a managerial solution for reduction of waste transfer to landfills. Home composting has many benefits. The use of household waste for the production of compost will result in a much smaller amount of waste being sent to landfills, which in turn will reduce the costs of waste collection, transportation and burial. Reducing the volume of waste for disposal and using them for the production of compost and plant fertilizer might help to recycle the material in a shorter time and to use them effectively in order to preserve the environment and reduce contamination. Producing compost in a home-based manner requires very small piece of land for preparation and recycling compared with other methods. The final product of home-made compost is valuable and helps to grow crops and garden plants. It is also used for modifying the soil structure and maintaining its moisture. The food that is transferred to landfills will spoil and produce leachate after a while. It will also release methane and greenhouse gases. But, composting these materials at home is the best way to manage degradable materials, use them efficiently and reduce environmental pollution. Studies have shown that the benefits of the sale of produced compost and the reduced costs of collecting, transporting, and burying waste can well be responsive to the costs of purchasing home compost machine and the cost of related trainings. Moreover, the process of producing home compost may be profitable within 4 to 5 years and as a result, it will have a major role in reducing waste management.

Keywords: compost, home compost, reducing waste, waste management

Procedia PDF Downloads 428

Authors: María Laura Guevara Campos

Abstract:

The increasing number of vending machines makes it easy for people to find them more frequently in stores, universities, workplaces, and even hospitals. These machines usually offer products with high contents of sugar and fat, which, if consumed regularly, can result in serious health threats, as overweight and obesity. Additionally, the energy consumption of these machines tends to be high, which has an impact on the environment as well. In order to promote the consumption of healthy food, a vending machine was designed to give the customer the opportunity to choose between a customized fruit salad and a customized fruit juice, both of them prepared instantly with the ingredients selected by the customer. The main parameters considered to design the machine were: the storage of the preferred fruits in a salad and/or in a juice according to a survey, the size of the machine, the use of ecologic recipients, and the overall energy consumption. The methodology used for the design was the one proposed by the German Association of Engineers for mechatronics systems, which breaks the design process in several stages, from the elaboration of a list of requirements through the establishment of the working principles and the design concepts to the final design of the machine, which was done in a 3D modelling software. Finally, with the design of this machine, the aim is to contribute to the development and implementation of healthier vending machines that offer freshly-made products, which is not being widely attended at present.

Keywords: design, design methodology, mechatronics systems, vending machines

Procedia PDF Downloads 133

Authors: Aida Safiera, Andika Dwi Rubyantoro, Muhammad Bagus Prakasa

Abstract:

Indonesia’s needs of diesel oil each year are increasing and getting urge. However, that problems are not supported by the amount of oil production that still low and also influenced by the fact of oil reserve is reduced. Because of that, the government prefers to import from other countries than fulfill the needs of diesel. To anticipate that problem, development of fuel based on renewable diesel is started. Renewable diesel is renewable alternative fuel that is hydrocarbon derivative from decarbonylation of non-edible oil. Indonesia is rich with natural resources, including nyamplung oil (Calophyllum inophyllum oil) and zeolite. Nyamplung oil (Calophyllum inophyllum oil) has many stearic acids which are useful on renewable diesel synthesis meanwhile zeolite is cheap. Zeolite is many used on high temperature reaction and cracking process on oil industry. Zeolite also has advantages which are a high crystallization, surface area and pores. In this research, the main focus that becomes our attention is on preparation and characterization of metal nanocrystal. Active site that used in this research is Nickel Molybdenum (NiMo). The advantage of nanocrystal with nano scale is having larger surface area. The synthesis of metal nanocrystal will be done with conventional preparation modification method that is called simple heating. Simple heating method is a metal nanocrystal synthesis method using continuous media which is polymer liquid. This method is a simple method and produces a small particles size in a short time. Influence of metal nanocrystal growth on this method is the heating profile. On the synthesis of nanocrystal, the manipulated variables are temperature and calcination time. Results to achieve from this research are diameter size on nano scale (< 100 nm) and uniform size without any agglomeration. Besides that, the conversion of synthesis of renewable diesel is high and has an equal specification with petroleum diesel. Catalyst activities are tested by FT-IR and GC-TCD on decarbonylation process with a pressure 15 bar and temperature 375 °C. The highest conversion from this reaction is 35% with selectivity around 43%.

Keywords: renewable diesel, simple heating, metal nanocrystal, NiMo, zeolite

Procedia PDF Downloads 231

Authors: Nihat Dipova, Bulent Cangir

Abstract:

This article presents the results of probabilistic seismic hazard analysis (PSHA) for Antalya (SW Turkey). South west of Turkey is characterized by large earthquakes resulting from the continental collision between the African, Arabian and Eurasian plates and crustal faults. Earthquakes around the study area are grouped into two; crustal earthquakes (D=0-50 km) and subduction zone earthquakes (50-140 km). Maximum observed magnitude of subduction earthquakes is Mw=6.0. Maximum magnitude of crustal earthquakes is Mw=6.6. Sources for crustal earthquakes are faults which are related with Isparta Angle and Cyprus Arc tectonic structures. A new earthquake catalogue for Antalya, with unified moment magnitude scale has been prepared and seismicity of the area around Antalya city has been evaluated by defining ‘a’ and ‘b’ parameters of the Gutenberg-Richter recurrence relationship. The Standard Cornell-McGuire method has been used for hazard computation utilizing CRISIS2007 software. Attenuation relationships proposed by Chiou and Youngs (2008) has been used for 0-50 km earthquakes and Youngs et. al (1997) for deep subduction earthquakes. Finally, Seismic hazard map for peak horizontal acceleration on a uniform site condition of firm rock (average shear wave velocity of about 1130 m/s) at a hazard level of 10% probability of exceedance in 50 years has been prepared.

Keywords: Antalya, peak ground acceleration, seismic hazard assessment, subduction

Procedia PDF Downloads 371