Search results for: Feynman formulas

Authors: Catarina Cruz, Ana Breda

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In the early years, until the children’s entrance at the elementary school, they are stimulated by their educators, through rich and attractive contexts, to explore and develop skills in different domains, from the socio-emotional to the cognitive. Many of these contexts trigger real or imaginary situations, familiar or not, through resources or pedagogical practices that incite children's curiosity, questioning, expression of ideas or emotions, social interaction, among others. Later, when children enter at the elementary school, their activity at school becomes more focused on developing skills in the cognitive domain, namely acquiring learning from different subject areas, such as Mathematics, Natural Sciences, History, among others. That is, to ensure that children develop the standardized learning recommended in the guiding curriculum documents, they spend part of their time applying formulas, memorizing information, following instructions, and so on, and in this way not much time is left to listen children, to learn about their interests and likes, as well as their perspective and questions about the surround world. In Elementary School, especially in the 1st Cycle, children are naturally curious, however, sometimes this skill is subtly conditioned by adults. Curious children learn more, since they have an intrinsic desire to know more, especially about what is unknown. When children think on subjects or themes that they are interested in or curious about, they attribute more meaning to this learning and retain it for longer. Therefore, it is important to approach subjects in the classroom that seduce or captivate children's attention, trigger them curiosity, and allow to hear their ideas. There are several resources, strategies and pedagogical practices to awaken children's curiosity, to explore their knowledge, to understand their perspectives and their way of thinking, to know a little more about their personality and to provide space for dialogue. The storytelling, its narrative’s exploration and interpretation is one of those pedagogical practices. Children’s literature, about real or imaginary subjects, stimulate children’s insights supported into their experiences, emotions, learnings and personality, and promote opportunities for children express freely their feelings and thoughts. This work focuses on a session developed with children in the 3rd year of schooling, from a Portuguese 1st Cycle Basic School, in which the story "From the Outside In and From the Inside Out" was presented. The story’s presentation was mainly centred on children’s activity, who read excerpts and interpreted/explored them through a dialogue led by one of the authors. The study presented here intends to show an example of how an exploration of a children's story can trigger ideas, thoughts, emotions or attitudes in children in the 3rd year of elementary school. To answer the research question, this work aimed to: identify ideas, thoughts, emotions or attitudes that emerged from the exploration of story; analyse aspects of the story and the orchestration/conduction of dialogue with/between children that facilitated or inhibited the emergence of ideas, thoughts, emotions or attitudes by children,

Keywords: storytelling, children’s perspectives, soft skills, non-formal learning contexts, orchestration

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Authors: Natalia Caldeira De Carvalho, Tassia Batista Pessato, Luis Gustavo R. Fernandes, Ricardo L. Zollner, Flavia Maria Netto

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Protein hydrolysates are ingredients of enteral diets and hypoallergenic formulas. Enzymatic hydrolysis is the most commonly used method for reducing the antigenicity of milk protein. The antigenicity and physicochemical characteristics of the protein hydrolysates depend on the reaction parameters. Among them, pH has been pointed out as of the major importance. Hydrolysis reaction in laboratory scale is commonly carried out under controlled pH (pH-stat). However, from the industrial point of view, controlling pH during hydrolysis reaction may be infeasible. This study evaluated the impact of pH control on the physicochemical properties and antigenicity of the hydrolysates of whey proteins with Alcalase. Whey protein isolate (WPI) solutions containing 3 and 7 % protein (w/v) were hydrolyzed with Alcalase 50 and 100 U g-1 protein at 60°C for 180 min. The reactions were carried out under controlled and uncontrolled pH conditions. Hydrolyses performed under controlled pH (pH-stat) were initially adjusted and maintained at pH 8.5. Hydrolyses carried out without pH control were initially adjusted to pH 8.5. Degree of hydrolysis (DH) was determined by OPA method, peptides profile was evaluated by HPLC-RP, and molecular mass distribution by SDS-PAGE/Tricine. The residual α-lactalbumin (α-La) and β-lactoglobulin (β-Lg) concentrations were determined using commercial ELISA kits. The specific IgE and IgG binding capacity of hydrolysates was evaluated by ELISA technique, using polyclonal antibodies obtained by immunization of female BALB/c mice with α-La, β-Lg and BSA. In hydrolysis under uncontrolled pH, the pH dropped from 8.5 to 7.0 during the first 15 min, remaining constant throughout the process. No significant difference was observed between the DH of the hydrolysates obtained under controlled and uncontrolled pH conditions. Although all hydrolysates showed hydrophilic character and low molecular mass peptides, hydrolysates obtained with and without pH control exhibited different chromatographic profiles. Hydrolysis under uncontrolled pH released, predominantly, peptides between 3.5 and 6.5 kDa, while hydrolysis under controlled pH released peptides smaller than 3.5 kDa. Hydrolysis with Alcalase under all conditions studied decreased by 99.9% the α-La and β-Lg concentrations in the hydrolysates detected by commercial kits. In general, β-Lg concentrations detected in the hydrolysates obtained under uncontrolled pH were significantly higher (p<0.05) than those detected in hydrolysates produced with pH control. The anti-α-La and anti-β-Lg IgE and IgG responses to all hydrolysates decreased significantly compared to WPI. Levels of specific IgE and IgG to the hydrolysates were below 25 and 12 ng ml-1, respectively. Despite the differences in peptide composition and α-La and β-Lg concentrations, no significant difference was found between IgE and IgG binding capacity of hydrolysates obtained with or without pH control. These results highlight the impact of pH on the hydrolysates characteristics and their concentrations of antigenic protein. Divergence between the antigen detection by commercial ELISA kits and specific IgE and IgG binding response was found in this study. This result shows that lower protein detection does not imply in lower protein antigenicity. Thus, the use of commercial kits for allergen contamination analysis should be cautious.

Keywords: allergy, enzymatic hydrolysis, milk protein, pH conditions, physicochemical characteristics

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Authors: Aleksandra Dudkowska, Gabriela Gic-Grusza

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Wind wave-induced sediment transport is an important multidimensional and multiscale dynamic process affecting coastal seabed changes and coastline evolution. The knowledge about sediment transport rate is important to solve many environmental and geotechnical issues. There are many types of sediment transport models but none of them is widely accepted. It is bacause the process is not fully defined. Another problem is a lack of sufficient measurment data to verify proposed hypothesis. There are different types of models for longshore sediment transport (LST, which is discussed in this work) and cross-shore transport which is related to different time and space scales of the processes. There are models describing bed-load transport (discussed in this work), suspended and total sediment transport. LST models use among the others the information about (i) the flow velocity near the bottom, which in case of wave-currents interaction in coastal zone is a separate problem (ii) critical bed shear stress that strongly depends on the type of sediment and complicates in the case of heterogeneous sediment. Moreover, LST rate is strongly dependant on the local environmental conditions. To organize existing knowledge a series of sediment transport models intercomparisons was carried out as a part of the project “Development of a predictive model of morphodynamic changes in the coastal zone”. Four classical one-grid-point models were studied and intercompared over wide range of bottom shear stress conditions, corresponding with wind-waves conditions appropriate for coastal zone in polish marine areas. The set of models comprises classical theories that assume simplified influence of turbulence on the sediment transport (Du Boys, Meyer-Peter & Muller, Ribberink, Engelund & Hansen). It turned out that the values of estimated longshore instantaneous mass sediment transport are in general in agreement with earlier studies and measurements conducted in the area of interest. However, none of the formulas really stands out from the rest as being particularly suitable for the test location over the whole analyzed flow velocity range. Therefore, based on the models discussed a new unified formula for longshore sediment transport rate estimation is introduced, which constitutes the main original result of this study. Sediment transport rate is calculated based on the bed shear stress and critical bed shear stress. The dependence of environmental conditions is expressed by one coefficient (in a form of constant or function) thus the model presented can be quite easily adjusted to the local conditions. The discussion of the importance of each model parameter for specific velocity ranges is carried out. Moreover, it is shown that the value of near-bottom flow velocity is the main determinant of longshore bed-load in storm conditions. Thus, the accuracy of the results depends less on the sediment transport model itself and more on the appropriate modeling of the near-bottom velocities.

Keywords: bedload transport, longshore sediment transport, sediment transport models, coastal zone

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Authors: Fong-Zuo Lee, Jihn-Sung Lai, Yung-Bin Lin, Xiaoqin Liu, Kuo-Chun Chang, Zhi-Xian Yang, Wen-Dar Guo, Jian-Hao Hong

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In recent years, climate change is a major factor to increase rainfall intensity and extreme rainfall frequency. The increased rainfall intensity and extreme rainfall frequency will increase the probability of flash flood with abundant sediment transport in a river basin. The floods caused by heavy rainfall may cause damages to the bridge, embankment, hydraulic works, and the other disasters. Therefore, the foundation scouring of bridge pier, embankment and spur dike caused by floods has been a severe problem in the worldwide. This severe problem has happened in many East Asian countries such as Taiwan and Japan because of these areas are suffered in typhoons, earthquakes, and flood events every year. Results from the complex interaction between fluid flow patterns caused by hydraulic works and the sediment transportation leading to the formation of river morphology, it is extremely difficult to develop a reliable and durable sensor to measure river bed degradation and bridge pier scouring. Therefore, an innovative scour monitoring sensor using vibration-based Micro-Electro Mechanical Systems (MEMS) was developed. This vibration-based MEMS sensor was packaged inside a stainless sphere with the proper protection of the full-filled resin, which can measure free vibration signals to detect scouring/deposition processes at the bridge pier. In addition, a friendly operational system includes rainfall runoff model, one-dimensional and two-dimensional numerical model, and the applicability of sediment transport equation and local scour formulas of bridge pier are included in this research. The friendly operational system carries out the simulation results of flood events that includes the elevation changes of river bed erosion near the specified bridge pier and the erosion depth around bridge piers. In addition, the system is developed with easy operation and integrated interface, the system can supplies users to calibrate and verify numerical model and display simulation results through the interface comparing to the scour monitoring sensors. To achieve the forecast of the erosion depth of river bed and main bridge pier in the study area, the system also connects the rainfall forecast data from Taiwan Typhoon and Flood Research Institute. The results can be provided available information for the management unit of river and bridge engineering in advance.

Keywords: flash flood, river bed degradation, bridge pier scouring, a friendly operational system

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Authors: Soraia V. M. de Sá, Miguel A. Faria, José O. Fernandes, Sara C. Cunha

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Cereals play a vital role in fulfilling the nutritional needs of children, supplying essential nutrients crucial for their growth and development. However, concerns arise due to children's heightened vulnerability due to their unique physiology, specific dietary requirements, and relatively higher intake in relation to their body weight. This vulnerability exposes them to harmful food contaminants, particularly mycotoxins, prevalent in cereals. Because of the thermal stability of mycotoxins, conventional industrial food processing often falls short of eliminating them. Children, especially those aged 4 months to 12 years, frequently encounter mycotoxins through the consumption of specialized food products, such as instant foods, breakfast cereals, bars, cookie snacks, fruit puree, and various dairy items. A close monitoring of this demographic group's exposure to mycotoxins is essential, as toxins ingestion may weaken children’s immune systems, reduce their resistance to infectious diseases, and potentially lead to cognitive impairments. The severe toxicity of mycotoxins, some of which are classified as carcinogenic, has spurred the establishment and ongoing revision of legislative limits on mycotoxin levels in food and feed globally. While EU Commission Regulation 1881/2006 addresses well-known mycotoxins in processed cereal-based foods and infant foods, the absence of regulations specifically addressing emerging mycotoxins underscores a glaring gap in the regulatory framework, necessitating immediate attention. Emerging mycotoxins have gained mounting scrutiny in recent years due to their pervasive presence in various foodstuffs, notably cereals and cereal-based products. Alarmingly, exposure to multiple mycotoxins is hypothesized to exhibit higher toxicity than isolated effects, raising particular concerns for products primarily aimed at children. This study scrutinizes the presence of 22 mycotoxins of the diverse range of chemical classes in 148 processed cereal-based foods, including 39 breakfast cereals, 25 infant formulas, 27 snacks, 25 cereal bars, and 32 cookies commercially available in Portugal. The analytical approach employed a modified QuEChERS procedure followed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. Given the paucity of information on the risk assessment of children to multiple mycotoxins in cereal and cereal-based products consumed by children of Portugal pioneers the evaluation of this critical aspect. Overall, aflatoxin B1 (AFB1) and aflatoxin G2 (AFG2) emerged as the most prevalent regulated mycotoxins, while enniatin B (ENNB) and sterigmatocystin (STG) were the most frequently detected emerging mycotoxins.

Keywords: cereal-based products, children´s nutrition, food safety, UPLC-MS/MS analysis

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Authors: Olga Sukhoveeva

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Carbon dioxide (CO2) is the main component of carbon biogeochemical cycle and one of the most important greenhouse gases (GHG). Agriculture, particularly arable soils, are one the largest sources of GHG emission for the atmosphere including CO2.Models may be used for estimation of GHG emission from agriculture if they can be adapted for different countries conditions. The only model used in officially at national level in United Kingdom and China for this purpose is DNDC (DeNitrification-DeComposition). In our research, the model DNDC is offered for estimation of GHG emission from arable soils in Russia. The aim of our research was to create the method of DNDC using for evaluation of CO2 emission in Russia based on official statistical information. The target territory was European part of Russia where many field experiments are located. At the first step of research the database on climate, soil and cropping characteristics for the target region from governmental, statistical, and literature sources were created. All-Russia Research Institute of Hydrometeorological Information – World Data Centre provides open daily data about average meteorological and climatic conditions. It must be calculated spatial average values of maximum and minimum air temperature and precipitation over the region. Spatial average values of soil characteristics (soil texture, bulk density, pH, soil organic carbon content) can be determined on the base of Union state register of soil recourses of Russia. Cropping technologies are published by agricultural research institutes and departments. We offer to define cropping system parameters (annual information about crop yields, amount and types of fertilizers and manure) on the base of the Federal State Statistics Service data. Content of carbon in plant biomass may be calculated via formulas developed and published by Ministry of Natural Resources and Environment of the Russian Federation. At the second step CO2 emission from soil in this region were calculated by DNDC. Modelling data were compared with empirical and literature data and good results were obtained, modelled values were equivalent to the measured ones. It was revealed that the DNDC model may be used to evaluate and forecast the CO2 emission from arable soils in Russia based on the official statistical information. Also, it can be used for creation of the program for decreasing GHG emission from arable soils to the atmosphere. Financial Support: fundamental scientific researching theme 0148-2014-0005 No 01201352499 ‘Solution of fundamental problems of analysis and forecast of Earth climatic system condition’ for 2014-2020; fundamental research program of Presidium of RAS No 51 ‘Climate change: causes, risks, consequences, problems of adaptation and regulation’ for 2018-2020.

Keywords: arable soils, carbon dioxide emission, DNDC model, European Russia

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Authors: Marcel Meinhardt, Manfred Keuser, Thomas Braml

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Cracking of reinforced concrete is a complex phenomenon induced by direct loads or restraints affecting reinforced concrete structures as soon as the tensile strength of the concrete is exceeded. Hence it is important to predict where cracks will be located and how they will propagate. The bond theory and the crack formulas in the actual design codes, for example, DIN EN 1992-1-1, are all based on the assumption that the reinforcement bars are embedded in homogeneous concrete without taking into account the influence of transverse reinforcement and the real stress situation. However, it can often be observed that real structures such as walls, slabs or beams show a crack spacing that is orientated to the transverse reinforcement bars or to the stirrups. In most Finite Element Analysis studies, the smeared crack approach is used for crack prediction. The disadvantage of this model is that the typical strain localization of a crack on element level can’t be seen. The crack propagation in concrete is a discontinuous process characterized by different factors such as the initial random distribution of defects or the scatter of material properties. Such behavior presupposes the elaboration of adequate models and methods of simulation because traditional mechanical approaches deal mainly with average material parameters. This paper concerned with the modelling of the initiation and the propagation of cracks in reinforced concrete structures considering the influence of transverse reinforcement and the real stress distribution in reinforced concrete (R/C) beams/plates in bending action. Therefore, a parameter study was carried out to investigate: (I) the influence of the transversal reinforcement to the stress distribution in concrete in bending mode and (II) the crack initiation in dependence of the diameter and distance of the transversal reinforcement to each other. The numerical investigations on the crack initiation and propagation were carried out with a 2D reinforced concrete structure subjected to quasi static loading and given boundary conditions. To model the uncertainty in the tensile strength of concrete in the Finite Element Analysis correlated normally and lognormally distributed random filed with different correlation lengths were generated. The paper also presents and discuss different methods to generate random fields, e.g. the Covariance Matrix Decomposition Method. For all computations, a plastic constitutive law with softening was used to model the crack initiation and the damage of the concrete in tension. It was found that the distributions of crack spacing and crack widths are highly dependent of the used random field. These distributions are validated to experimental studies on R/C panels which were carried out at the Laboratory for Structural Engineering at the University of the German Armed Forces in Munich. Also, a recommendation for parameters of the random field for realistic modelling the uncertainty of the tensile strength is given. The aim of this research was to show a method in which the localization of strains and cracks as well as the influence of transverse reinforcement on the crack initiation and propagation in Finite Element Analysis can be seen.

Keywords: crack initiation, crack modelling, crack propagation, cracks, numerical simulation, random fields, reinforced concrete, stochastic

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Authors: Tuğrul Varol, Halil Barış Özel

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In this study which has been conducted in Akçasu Forest Range District of Devrek Forest Directorate; 3 methods (cover removal with human force, cover removal with Hitachi F20 Excavator, and cover removal with agricultural equipment mounted on a Ferguson 240S agriculture tractor) utilized in weed control efforts in regeneration of degraded oriental beech forests have been compared. In this respect, 3 methods have been compared by determining certain work hours and standard durations of unit areas (1 hectare). For this purpose, evaluating the tasks made with human and machine force from the aspects of duration, productivity and costs, it has been aimed to determine the most productive method in accordance with the actual ecological conditions of research field. Within the scope of the study, the time studies have been conducted for 3 methods used in weed control efforts. While carrying out those studies, the performed implementations have been evaluated by dividing them into business stages. Also, the actual data have been used while calculating the cost accounts. In those calculations, the latest formulas and equations which are also used in developed countries have been utilized. The variance of analysis (ANOVA) was used in order to determine whether there is any statistically significant difference among obtained results, and the Duncan test was used for grouping if there is significant difference. According to the measurements and findings carried out within the scope of this study, it has been found during living cover removal efforts in regeneration efforts in demolished oriental beech forests that the removal of weed layer in 1 hectare of field has taken 920 hours with human force, 15.1 hours with excavator and 60 hours with an equipment mounted on a tractor. On the other hand, it has been determined that the cost of removal of living cover in unit area (1 hectare) was 3220.00 TL for man power, 788.70 TL for excavator and 2227.20 TL for equipment mounted on a tractor. According to the obtained results, it has been found that the utilization of excavator in weed control effort in regeneration of degraded oriental beech regions under actual ecological conditions of research field has been found to be more productive from both of aspects of duration and costs. These determinations carried out should be repeated in weed control efforts in degraded forest fields with different ecological conditions, it is compulsory for finding the most efficient weed control method. These findings will light the way of technical staff of forestry directorate in determination of the most effective and economic weed contol method. Thus, the more actual data will be used while preparing the weed control budgets, and there will be significant contributions to national economy. Also the results of this and similar studies are very important for developing the policies for our forestry in short and long term.

Keywords: artificial regeneration, weed control, oriental beech, productivity, mechanization, man power, cost analysis

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Authors: Mustafa Metin Donma, Orkide Donma

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Childhood obesity is an important clinical problem because it may lead to chronic diseases during the adulthood period of the individual. Obesity is a metabolic disease associated with low-grade inflammation. The liver occurs at the center of metabolic pathways. Adropin, fibroblast growth factor-21 (FGF-21), and fetuin-A are hepatokines. Due to the immense participation of the liver in glucose metabolism, these liver-derived factors may be associated with insulin resistance (IR), which is a phenomenon discussed within the scope of obesity problems. The aim of this study is to determine the concentrations of adropin, FGF-21, and fetuin-A in childhood obesity, to point out possible differences between the obesity groups, and to investigate possible associations among these three hepatokines in obese and morbidly obese children. A total of one hundred and thirty-two children were included in the study. Two obese groups were constituted. The groups were matched in terms of mean ± SD values of ages. Body mass index values of obese and morbidly obese groups were 25.0 ± 3.5 kg/m² and 29.8 ± 5.7 kg/m², respectively. Anthropometric measurements including waist circumference, hip circumference, head circumference, and neck circumference were recorded. Informed consent forms were taken from the parents of the participants. The ethics committee of the institution approved the study protocol. Blood samples were obtained after overnight fasting. Routine biochemical tests, including glucose- and lipid-related parameters, were performed. Concentrations of the hepatokines (adropin, FGF-21, fetuin A) were determined by enzyme-linked immunosorbent assay. Insulin resistance indices such as homeostasis model assessment for IR (HOMA-IR), alanine transaminase-to aspartate transaminase ratio (ALT/AST), diagnostic obesity notation model assessment laboratory index, diagnostic obesity notation model assessment metabolic syndrome index as well as obesity indices such as diagnostic obesity notation model assessment-II index, and fat mass index were calculated using the previously derived formulas. Statistical evaluation of the study data as well as findings of the study was performed by SPSS for Windows. Statistical difference was accepted significant when p is smaller than 0.05. Statistically significant differences were found for insulin, triglyceride, high-density lipoprotein cholesterol levels of the groups. A significant increase was observed for FGF-21 concentrations in the morbidly obese group. Higher adropin and fetuin-A concentrations were observed in the same group in comparison with the values detected in the obese group (p > 0.05). There was no statistically significant difference between the ALT/AST values of the groups. In all of the remaining IR and obesity indices, significantly increased values were calculated for morbidly obese children. Significant correlations were detected between HOMA-IR and each of the hepatokines. The highest one was the association with fetuin-A (r=0.373, p=0.001). In conclusion, increased levels observed in adropin, FGF-21, and fetuin-A have shown that these hepatokines possess increasing potential going from obese to morbid obese state. Out of the correlations found with the IR index, the most affected hepatokine was fetuin-A, the parameter possibly used as the indicator of the advanced obesity stage.

Keywords: adropin, fetuin A, fibroblast growth factor-21, insulin resistance, pediatric obesity

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Authors: Hend Ben Tkhayat , Khaled Al Zahabi, Husam Younes

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Introduction: Vildagliptin (VG), a dipeptidyl peptidase-4 inhibitor (DPP-4), was proven to be an active agent for the treatment of type 2 diabetes. VG works by enhancing and prolonging the activity of incretins which improves insulin secretion and decreases glucagon release, therefore lowering blood glucose level. It is usually used with various classes, such as insulin sensitizers or metformin. VG is currently only marketed as an immediate-release tablet that is administered twice daily. In this project, we aim to formulate an extended-release with a zero-order profile tableted lipid microparticles of VG that could be administered once daily ensuring the patient’s convenience. Method: The spray-congealing technique was used to prepare VG microparticles. Compritol® was heated at 10 oC above its melting point and VG was dispersed in the molten carrier using a homogenizer (IKA T25- USA) set at 13000 rpm. VG dispersed in the molten Compritol® was added dropwise to the molten Gelucire® 50/13 and PEG® (400, 6000, and 35000) in different ratios under manual stirring. The molten mixture was homogenized and Carbomer® amount was added. The melt was pumped through the two-fluid nozzle of the Buchi® Spray-Congealer (Buchi B-290, Switzerland) using a Pump drive (Master flex, USA) connected to a silicone tubing wrapped with silicone heating tape heated at the same temperature of the pumped mix. The physicochemical properties of the produced VG-loaded microparticles were characterized using Mastersizer, Scanning Electron Microscope (SEM), Differential Scanning Calorimeter (DSC) and X‐Ray Diffractometer (XRD). VG microparticles were then pressed into tablets using a single punch tablet machine (YDP-12, Minhua pharmaceutical Co. China) and in vitro dissolution study was investigated using Agilent Dissolution Tester (Agilent, USA). The dissolution test was carried out at 37±0.5 °C for 24 hours in three different dissolution media and time phases. The quantitative analysis of VG in samples was realized using a validated High-Pressure Liquid Chromatography (HPLC-UV) method. Results: The microparticles were spherical in shape with narrow distribution and smooth surface. DSC and XRD analyses confirmed the crystallinity of VG that was lost after being incorporated into the amorphous polymers. The total yields of the different formulas were between 70% and 80%. The VG content in the microparticles was found to be between 99% and 106%. The in vitro dissolution study showed that VG was released from the tableted particles in a controlled fashion. The adjustment of the hydrophilic/hydrophobic ratio of excipients, their concentration and the molecular weight of the used carriers resulted in tablets with zero-order kinetics. The Gelucire 50/13®, a hydrophilic polymer was characterized by a time-dependent profile with an important burst effect that was decreased by adding Compritol® as a lipophilic carrier to retard the release of VG which is highly soluble in water. PEG® (400,6000 and 35 000) were used for their gelling effect that led to a constant rate delivery and achieving a zero-order profile. Conclusion: Tableted spray-congealed lipid microparticles for extended-release of VG were successfully prepared and a zero-order profile was achieved.

Keywords: vildagliptin, spray congealing, microparticles, controlled release

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Authors: Hoda Manafian, Stephen Holland

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Problem statement: Rural areas in Iran are one of the most popular tourism destinations. Abyaneh Village is one of them with a long history behind it (more than 1500 years) which is a national heritage site and also is nominated as a world heritage site in UNESCO tentative list from 2007. There is a considerable foundation of religious-cultural heritage and also agricultural history and activities. However, this heritage site suffers from mass tourism which is beyond its social and physical carrying capacity, since the annual number of tourists exceed 500,000. While there are four adjacent villages around Abyaneh which can benefit from advantages of tourism. Local managers also can at the same time prorate the tourists’ flux of Abyaneh on those other villages especially in high-season. The other villages have some cultural and natural tourism attractions as well. Goal: The main goal of this study is to identify a feasible development strategy according to the current strengths, weaknesses, opportunities and threats of rural tourism in this area (Abyaneh Village and four adjacent villages). This development strategy can lead to sustainable management of these destinations. Method: To this end, we used SWOT analysis as a well-established tool for conducting a situational analysis to define a sustainable development strategy. The procedures included following steps: 1) Extracting variables of SWOT chart based on interviewing tourism experts (n=13), local elites (n=17) and personal observations of researcher. 2) Ranking the extracted variables from 1-5 by 13 tourism experts in Isfahan Cultural Heritage, Handcrafts and Tourism Organization (ICHTO). 3) Assigning weights to the ranked variables using Expert Choice Software and the method of Analytical Hierarchical Process (AHP). 4) Defining the Total Weighted Score (TWS) for each part of SWOT chart. 5) Identifying the strategic position according to the TWS 6) Selecting the best development strategy based on the defined position using the Strategic Position and Action Evaluation (SPACE) matrix. 7) Assessing the Probability of Strategic Success (PSS) for the preferred strategy using relevant formulas. 8) Defining two feasible alternatives for sustainable development. Results and recommendations: Cultural heritage attractions were first-ranked variable in strength chart and also lack of sufficient amenities for one-day tourists (catering, restrooms, parking, and accommodation) was firs-ranked weakness. The strategic position was in ST (Strength-Threat) quadrant which is a maxi-mini position. According this position we would suggest ‘Competitive Strategy’ as a development strategy which means relying on strengths in order to neutralization threats. The result of Probability of Strategic Success assessment which was 0.6 shows that this strategy could be successful. The preferred approach for competitive strategy could be rebranding the market of tourism in this area. Rebranding the market can be achieved by two main alternatives which are based on the current strengths and threats: 1) Defining a ‘Heritage Corridor’ from first adjacent village to Abyaneh as a final destination. 2) Focus on ‘educational tourism’ versus mass tourism and also green tourism by developing agritourism in that corridor.

Keywords: Abyaneh village, rural tourism, SWOT analysis, sustainable strategies

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Authors: Sebastian Kehne, Alexander Epple, Werner Herfs

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A new method for optimal selection of components for multi-axes forward-feed drive systems is proposed in which the choice of motors, gear boxes and ball screw drives is optimized. Essential is here the synchronization of electrical and mechanical frequency behavior of all axes because even advanced controls (like H∞-controls) can only control a small part of the mechanical modes – namely only those of observable and controllable states whose value can be derived from the positions of extern linear length measurement systems and/or rotary encoders on the motor or gear box shafts. Further problems are the unknown processing forces like cutting forces in machine tools during normal operation which make the estimation and control via an observer even more difficult. To start with, the open source Modelica Feed Drive Library which was developed at the Laboratory for Machine Tools, and Production Engineering (WZL) is extended from one axis design to the multi axes design. It is capable to simulate the mechanical, electrical and thermal behavior of permanent magnet synchronous machines with inverters, different gear boxes and ball screw drives in a mechanical system. To keep the calculation time down analytical equations are used for field and torque producing equivalent circuit, heat dissipation and mechanical torque at the shaft. As a first step, a small machine tool with a working area of 635 x 315 x 420 mm is taken apart, and the mechanical transfer behavior is measured with an impulse hammer and acceleration sensors. With the frequency transfer functions, a mechanical finite element model is built up which is reduced with substructure coupling to a mass-damper system which models the most important modes of the axes. The model is modelled with Modelica Feed Drive Library and validated by further relative measurements between machine table and spindle holder with a piezo actor and acceleration sensors. In a next step, the choice of possible components in motor catalogues is limited by derived analytical formulas which are based on well-known metrics to gain effective power and torque of the components. The simulation in Modelica is run with different permanent magnet synchronous motors, gear boxes and ball screw drives from different suppliers. To speed up the optimization different black-box optimization methods (Surrogate-based, gradient-based and evolutionary) are tested on the case. The objective that was chosen is to minimize the integral of the deviations if a step is given on the position controls of the different axes. Small values are good measures for a high dynamic axes. In each iteration (evaluation of one set of components) the control variables are adjusted automatically to have an overshoot less than 1%. It is obtained that the order of the components in optimization problem has a deep impact on the speed of the black-box optimization. An approach to do efficient black-box optimization for multi-axes design is presented in the last part. The authors would like to thank the German Research Foundation DFG for financial support of the project “Optimierung des mechatronischen Entwurfs von mehrachsigen Antriebssystemen (HE 5386/14-1 | 6954/4-1)” (English: Optimization of the Mechatronic Design of Multi-Axes Drive Systems).

Keywords: ball screw drive design, discrete optimization, forward feed drives, gear box design, linear drives, machine tools, motor design, multi-axes design

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Authors: Claudio Loconsole, Daniele Leonardis, Antonio Brunetti, Gianpaolo Francesco Trotta, Nicholas Caporusso, Vitoantonio Bevilacqua

Abstract:

Unfortunately, many people still do not have access to communication, with specific regard to reading and writing. Among them, people who are blind or visually impaired, have several difficulties in getting access to the world, compared to the sighted. Indeed, despite technology advancement and cost reduction, nowadays assistive devices are still expensive such as Braille-based input/output systems which enable reading and writing texts (e.g., personal notes, documents). As a consequence, assistive technology affordability is fundamental in supporting the visually impaired in communication, learning, and social inclusion. This, in turn, has serious consequences in terms of equal access to opportunities, freedom of expression, and actual and independent participation to a society designed for the sighted. Moreover, the visually impaired experience difficulties in recognizing objects and interacting with devices in any activities of daily living. It is not a case that Braille indications are commonly reported only on medicine boxes and elevator keypads. Several software applications for the automatic translation of written text into speech (e.g., Text-To-Speech - TTS) enable reading pieces of documents. However, apart from simple tasks, in many circumstances TTS software is not suitable for understanding very complicated pieces of text requiring to dwell more on specific portions (e.g., mathematical formulas or Greek text). In addition, the experience of reading\writing text is completely different both in terms of engagement, and from an educational perspective. Statistics on the employment rate of blind people show that learning to read and write provides the visually impaired with up to 80% more opportunities of finding a job. Especially in higher educational levels, where the ability to digest very complex text is key, accessibility and availability of Braille plays a fundamental role in reducing drop-out rate of the visually impaired, thus affecting the effectiveness of the constitutional right to get access to education. In this context, the Braille Lab project aims at overcoming these social needs by including affordability in designing and developing assistive tools for visually impaired people. In detail, our awarded project focuses on a technology innovation of the operation principle of existing assistive tools for the visually impaired leaving the Human-Machine Interface unchanged. This can result in a significant reduction of the production costs and consequently of tool selling prices, thus representing an important opportunity for social entrepreneurship. The first two assistive tools designed within the Braille Lab project following the proposed approach aims to provide the possibility to personally print documents and handouts and to read texts written in Braille using refreshable Braille display, respectively. The former, named ‘Braille Cartridge’, represents an alternative solution for printing in Braille and consists in the realization of an electronic-controlled dispenser printing (cartridge) which can be integrated within traditional ink-jet printers, in order to leverage the efficiency and cost of the device mechanical structure which are already being used. The latter, named ‘Braille Cursor’, is an innovative Braille display featuring a substantial technology innovation by means of a unique cursor virtualizing Braille cells, thus limiting the number of active pins needed for Braille characters.

Keywords: Human rights, social challenges and technology innovations, visually impaired, affordability, assistive tools

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