Rectangular Test Research Articles

Obesity and associated factors among students in Inner Mongolia in 2019

Objective To understand the prevalence of obesity and its associations with diet, exercise and mental health among students in Inner Mongolia, so as to provide scientific basis for the formulation of obesity intervention measures for students in this area. Methods Stratified and cluster random sampling was used to select 186 649 students from all 12 cities and 103 banners and counties in Inner Mongolia Autonomous region. All the participants were divided into groups according to the BMI classification criteria for overweight/obesity screening of Chinese school-age children and adolescents (kg/m 2). Univariate analysis was carried out by means of rectangular χ 2 test, and multivariate unconditional Logistic regression model was used to screen the risk factors of obesity. Results The overall obesity rate was 18.54%, the obesity rate of boys was 22.04%, and the obesity rate of girls was 14.99%. The results of multivariate Logistic regression analysis showed that area ( OR = 0.79), sex ( OR = 0.61), times of eating fried food per day ( OR = 1.08), daily exercise for more than 60 minutes per week >2 days ( OR = 0.89), eat breakfast every day ( OR = 0.86), times of drinking drinks per day ( OR = 1.12), Smoking ( OR = 0.87), drinking ( OR = 1.07), eating fruit per day ( OR = 1.07), watching TV ≥2 hours a day ( OR = 1.06), sleeping time ( OR = 0.93) and school period may be related to obesity ( P<0.05). Conclusion The overall obesity rate of students in Inner Mongolia is relatively high, and the occurrence of obesity is related to diet, exercise behavior, living habits and psychological factors. 【摘要】 目的 了解内蒙古地区学生肥胖现状及其与饮食、运动、心理等方面的关系, 为制定该地区学生肥胖干预措施提 供科学依据。 方法 采用分层整群随机抽样方法, 抽取内蒙古自治区全部12个盟市、103个旗县区的186 649名学生。按 中国学龄儿童青少年超重与肥胖筛査标准对调査对象进行分组, 采用妒检验进行单因素分析, 采用多因素非条件Logistic 回归模型筛选肥胖有关因素。 结果 学生总体肥胖率为18.54%, 男生肥胖率为22.04%, 女生为14.99%。多因素Logistic 回归分析结果显示, 监测点 ( OR = 0.79)、性别 ( OR = 0.61)、每日吃油炸食品次数 ( OR =1.08)、每周每日运动超过60 min>2 d ( OR = 0.89)、是否每天吃早餐 ( OR = 0.86)、每日喝饮料次数 ( OR = 1.12)、吸烟 ( OR = 0.87)、饮酒 ( OR = 1.07)、每日吃水果次 数 ( OR =1.07)、每日看电视 ≥2 h ( OR =1.06)、睡眠时间 ( OR = 0.93)以及学段可能与学生肥胖有关 ( P值均<0.05)。 结论 内蒙古地区学生总体肥胖率较髙, 学生肥胖的发生与饮食运动行为、生活习惯及心理因素有关。应采取针对性干预措施控 制学生肥胖的发生。

8-Week Supplementation of 2S-Hesperidin Modulates Antioxidant and Inflammatory Status after Exercise until Exhaustion in Amateur Cyclists.

Both acute and chronic ingestion of 2S-hesperidin have shown antioxidant and anti-inflammatory effects in animal studies, but so far, no one has studied this effect of chronic ingestion in humans. The main objective was to evaluate whether an 8-week intake of 2S-hesperidin had the ability to modulate antioxidant-oxidant and inflammatory status in amateur cyclists. A parallel, randomized, double-blind, placebo-controlled trial study was carried out with two groups (500 mg/d 2S-hesperidin; n = 20 and 500 mg/d placebo; n = 20). An incremental test was performed to determine the working zones in a rectangular test, which was used to analyze for changes in antioxidant and inflammatory biomarkers. After 2S-hesperidin ingestion, we found in the rectangular test: (1) an increase in superoxide dismutase (SOD) after the exercise phase until exhaustion (p = 0.045) and the acute recovery phase (p = 0.004), (2) a decrease in the area under the oxidized glutathione curve (GSSG) (p = 0.016), and (3) a decrease in monocyte chemoattractant protein 1 (MCP1) after the acute recovery phase (p = 0.004), post-intervention. Chronic 2S-hesperidin supplementation increased endogenous antioxidant capacity (↑SOD) after maximal effort and decreased oxidative stress (↓AUC-GSSG) during the rectangular test, decreasing inflammation (↓MCP1) after the acute recovery phase.

Study of Wall Static Pressure Distribution on Flat Surface by Impinging Submerged Jet from Non-circular Orifice

The distribution of wall static and stagnation (CP and CPO) pressure coefficient on a flat rectangular element by impinging air jet from the hexagonal orifice is obtained from experimentation. The past research studies helped to identify key parameters such as orifice geometry, jet exit-to-plate-distance (Z/dj), test section inclination (θ), jet Reynold number (Re), lateral distance-to-jet diameter (X/dj), test surface type and geometry, for better and acceptable results. The experimental outcome helps to know the effect of identified key parameters on wall static and stagnation pressure on a rectangular test plate in a confined flow path. The independent nature of wall static pressure is observed for all jet Reynold number (10000 ≤ Re ≤ 50000). Higher pressure coefficient values were observed at lower Z/dj = 1, X/dj = 0 and θ = 0. A significant drop in CP values are seen with the increase in Z/dj, X/dj and θ. The experimental CP and CPO contribution of confined flow are compared against the unconfined flow, around 48% to 58% enhancement is observed when confinement is used. Experimental pressure drop measurements across orifice were made and pressure loss coefficient (PC) for hexagonal orifice of confined and unconfined condition are reported.

Effect of photobiomodulation therapy on performance and running economy in runners: A randomized double-blinded placebo-controlled trial

ABSTRACT The objective of this study was to evaluate effects of photobiomodulation therapy (PBMT) on the 3000 m running performance (primary outcome), running economy (RE), metabolic cost and ratings of perceived exertion during running (secondary outcomes). Twenty male endurance athletes performed 4-min treadmill rectangular test at 12 km.h-1 monitored by a gas analyser. After that, PBMT or placebo in each lower limb was applied, followed performed a maximum test of 3000 m. Immediately after 3000 m test, the athletes repeated the treadmill test. Another application of PBMT/placebo was done after the treadmill test, and athletes went back to the laboratory 24 h later to repeat the treadmill test. After a 72 h interval, athletes repeated all procedures with another treatment intervention (PBMT/placebo). Athletes performed the 3000 m running test ~7s faster when treated with PBMT with similar effort score compared placebo condition. The RE remains unchanged immediately post 3000 m running test, nonetheless RE measured post-24 h improved by 5% with PBMT application without changes in metabolic cost. The PBMT pre- and post-conditioning enhanced the 3000 m running performance and improved RE 24 h following the 3000 m test. However, no changes on ratings of perceived exertion and metabolic cost with the application of PBMT.

Моделирование температурного режима, мониторинг и прогнозирование перегрева болтовых контактных соединений токоведущих шин

The widely used infrared imaging control of bolted connections in live rectangular buses is performed without direct access to the object being diagnosed. This gives only an approximate idea of the contact state, whereas the contact layer condition remains poorly known. The high thermal conductivity of the live bus material makes the thermal field pattern near the contact connection rather soft, which significantly adds complexity to the diagnostics. Therefore, it is important to develop diagnostics of contact connections by dynamic methods based on analyzing the thermal effect of rectangular test or quasi-rectangular operational current pulses in the busbars of electrical installations. By analyzing the temperature field dynamics in the flat contact zone it becomes possible to establish a functional relationship between the contact zone temperature and the bus free surface temperature, and also the relationship between the temperature recorded on the bus surface and the transition resistance, which is the contact quality characteristic. It has been shown, by simulating the contact surface temperature control in the dynamic monitoring mode, that it is possible to determine the rectangular bus bolted connection overheating protection response time. It is proposed to use the obtained dependence as a conversion function for an intelligent electrical contact temperature sensor.

Формирование признакового пространства периодических временных зависимостей для систем диагностики состояния динамических объектов на примере сетчатки глаза

The technology of testing dynamically and structurally similar aircraft models for flutter in subsonic wind tunnels using information and The article addresses techniques for setting up the attribute space of informative features of periodic signals recorded at the output of a dynamic object with an unknown structure in response to rectangular testing signals of different frequencies applied to the object input. The attribute space is used in developing expert systems for diagnosing the current state of an operating dynamic object. With a great variety of possible developing faults, the simplest practical techniques involving the use of characteristic points of change in the observed time dependencies yield a limited number of features with large mutual intersection domains. To expand the attribute space, it is proposed to use the expansion of input and output signals into a Fourier series for setting up a base of additional features. The proposed features characterize, depending on the testing conditions, the object’s transferring properties in the frequency domain from changes in its amplitude and phase characteristics. The test pulse frequency and duration serve as such conditions. For the convenience of comparing the object’s frequency responses variation pattern, two special procedures are used. The first procedure allows the observed time dependencies to be reduced to a single pseudo frequency of the test signals. The second procedure uses specially formed windows for subjecting individual fragments of the observed time dependencies to a spectral analysis. It is shown that, depending on the type of the frequency responses being analyzed, the techniques for their polynomial approximation, as well as integral estimates of frequency response individual domains can be useful. The polynomial approximation makes it possible to use the coefficients of the approximating polynomials as additional features, and the integration of individual characteristic domains of the frequency responses makes it possible to introduce dimensionless relative indicators that characterize the degree of change in the frequency responses depending on the experimental conditions. The considered techniques open the possibility to select additional features that can help distinguish both separate groups of faults and individual faults in operating objects. The study results are illustrated by the examples of analyzing the changes in electroretinograms that record changes in the eye retina biopotential in response to light flashes of different frequencies.

Bazı Yerel Çerezlik Ayçiçeği (Helianthus annuus L.) Populasyonlarında Verim ve Verim Öğelerinin Belirlenmesi

Bu çalışmada, Türkiye’nin farklı bölgelerinden toplanan bazı yerel çerezlik ayçiçeği popülasyonların Tokat ekolojik koşullarında verim ve verim unsurlarının belirlenmesi amaçlanmıştır. Araştırma Tokat-Kazova ekolojik koşullarında dikdörtgen latis deneme desenine” göre, 3 tekerrürlü olarak, 2 yıl süre ile yürütülmüştür. Araştırmada bitki boyu, tabla çapı, tane eni, tane boyu, 1000 tane ağırlığı ve tohum verimi incelenmiştir. Projede materyal olarak ülkemizin farklı bölgelerinden toplanmış, 20 adet çerezlik ayçiçeği yerel populasyonu ile standart olarak iki adet tescilli çeşit kullanılmıştır. İki yılın ortalama sonuçlarına göre; bitki boyu değerleri 154.3-265.4 cm arasında, tabla çapı 17.0-22.2 cm, tane eni 7.9-9.6 mm, tane boyu 20.4-25.9 mm, 1000 tane ağırlığı 122.2-167.1 g ve tohum verimi 180.4-474.0 kg/da arasında değişmiştir. Araştırmada incelenen özellikler birlikte değerlendirildiğinde 16, 3, 10, 13 ve 14 no’lu populasyonların ön plana çıktığı görülmüştür.

Local flow structure and turbulence quantities inside a heated rectangular riser in turbulent forced and mixed convection heat transfers

Heat transfer deterioration in turbulent mixed convection affects the performance and safety of various pieces of industrial equipment. The reactor cavity cooling system (RCCS), a passive safety system in a very high temperature gas-cooled nuclear reactor (VHTR), incorporates rectangular riser channels to remove residual heat emitted from the reactor vessel, where turbulent mixed convection may occur under some emergency operation conditions. Understanding the heat transfer phenomena in the RCCS riser duct is, therefore, important to ensure the safety of the VHTR. To investigate the heat transfer phenomena inside a heated rectangular duct, a visualization experiment was carried out to obtain the local flow structure and turbulence quantities in turbulent forced and mixed convection heat transfers. Using the particle image velocimetry method, the velocity fields inside the heated test section were captured and time-averaged velocity distributions and root-mean-square velocity fluctuation distributions were obtained under various experimental conditions. Inside a rectangular test section, the flow had a nonaxisymmetric Reynolds shear stress distribution, related to secondary flows near the corner of the test section. According to the overall distributions of the local velocity and turbulence quantities under various experimental conditions, the mechanism of the heat transfer deterioration inside a heated rectangular riser was investigated in relation to the distribution of the Reynolds shear stress. Inside the rectangular test section with the intense buoyancy force, flow laminarization near the corner was preceded by that of the center with decreases in secondary flows and Reynolds shear stress distribution near the corner, which indicate a transition from forced to mixed convection. According to these results of the visualization experiments, it was estimated that the heat transfer deterioration in the rectangular riser would be affected by the aspect ratio of the test section.

Design of square and rectangular CFST cross-sectional capacities in compression

Eurocode EN 1994-1-1 currently covers design of concrete-filled steel tubular (CFST) columns using normal strength materials with nominal steel yield strength (fy) not more than 460 MPa and concrete characteristic cylinder strength less than 50 MPa. As high strength materials have been increasingly used in construction, this paper aims to extend current design equation for square and rectangular CFSTs in EN 1994-1-1 to incorporate high strength materials. A comprehensive experimental database consisting of 443 square and rectangular CFST stub column test results was developed. Statistical evaluations were undertaken and the results indicate that the current cross-section slenderness limit for square and rectangular CFSTs is too conservative and can be safely relaxed from 52235/fy to 68235/fy. The design equation could be extended to incorporate high strength materials). Then, a reliability analysis in accordance with EN 1990 was performed to evaluate the applicability of the proposed design method. It was found that the current partial factors are safe for the design of square and rectangular CFSTs with normal strength materials even after relaxation of the cross-section slenderness limit. However, modification should be applied to the existing design equation for the design of high strength materials to yield an acceptable safety level. Finally, an experimental investigation on 10 stub column tests was carried out to further verify the applicability of the proposed design recommendation. It was found that the proposed design recommendation yields satisfactory predictions when compared to test results.

Use of digital correlation techniques for investigating behaviour of geothermal driven piles

Geothermal energy has established its huge potential as renewable source of energy for general building establishments. A key feature here is the use of energy piles which serve as major energy exchange system which is sustainable and low-cost. Energy piles are basically driven precast piles employed to provide structural support to structures and act as heat exchange units to provide heating / cooling to buildings. The behaviour of energy piles is influenced by temperature, physical and engineering properties of soil. However, uncertainty still exists at pile soil interface irrespective of its heating or cooling conditions. The present study examines the suitability of using digital correlation technique (DIC) namely GeoPIV-RG software to study the soil deformation at pile soil interface in sandy soil. A rectangular test tank made of steel with a size of 60 × 20 × 45 cm is used for experimental studies. Hollow half section aluminum piles closed at the ends with two different pile length to outer pile diameter ratios viz., 10 and 15 of same flexural rigidity are used for the experimental studies. The piles are subjected to sustained loading simulated through Universal testing machine and movements of soil around the pile are captured using a digital camera. The image analysis software named GeoPIV-RG is used to determine the shear strains and soil displacements. Analysis of results indicated that this technique could capture deformation characteristics and surface heave formation in the surrounding infill medium.

Wrinkling Prediction of Rectangular Cup Deep Drawing Process for Aluminum Alloy Sheets by Using the Modified Yoshida Buckling Test

Nowadays, the industry has been growing interest in lightweight material for automotive and cookware manufacturing. The formability of sheet material is an important issue in these industries. The wrinkling behavior is one of the most failure in sheet metal forming and is often occurred in deep drawing process in cookware manufacturing. In this work, the developed wrinkling limit curves (WLCs) using experimental and numerical simulation of a modified Yoshida buckling test were precisely used to predict the wrinkling behavior of rectangular cup deep drawing for aluminum alloy sheets grade AA5054-O and AA5052-H32. The Industrial parts, the rectangular cup deep drawing was firstly performed for both investigated aluminum sheets for obtaining the wrinkling initiation on the side wall area of deep drawing parts. Subsequently, the experimental formed parts were carefully measured the draw-in of deformed blank sheets and drawing depth to validate the finite element (FE) model. Then, the FE simulation of the corresponding drawing tests were calculated, by which were implemented with the Hill’48 yield criterion and Swift hardening law to descript anisotropic plastic deformation. As a result, the local principle Major and Minor principle strains of observed wrinkle areas were gathered in the side wall area of the rectangular cup deep drawing test. Finally, the developed WLCs of aluminum alloy sheets were applied to predict the wrinkling formation of the formed deep drawing parts. Comparatively, the influence of different aluminum alloy grades on the WLCs and wrinkling behavior were explicitly investigated.

Development of critical heat flux correlation for In-vessel retention

ABSTRACT In-vessel retention (IVR) is a strategy for severe accident management in which the lower head of the reactor vessel is submerged in a water-flooded reactor cavity. Critical heat flux (CHF) data for IVR are important for estimating cooling capacity of the reactor vessel. The existing CHF data for IVR which were obtained for the specific geometries and thermal-hydraulic conditions of actual plants are difficult to be applied to plants with other specifications. Hence, the purpose of this study is to develop CHF correlations applicable to various pressurized water reactor plants in a wide range of thermal outputs based on newly obtained CHF data. A rectangular test section with a cross-section of 150 mm × 150 mm and length of 600 mm was used for simulating a cooling channel. The thermal-hydraulic conditions expected in actual plants were studied, and the results were used in the experiment. The effects of parameters such as pressure, mass flux, thermodynamic quality, and angle on CHF were investigated . Based on these results, we developed a CHF correlation formula that can be applied to a wider range than previously, up to a maximum heat flux of 3000 kW/m2, and that predicts CHF with an error of ± 10%.

Effect of Combining Fiber and Textile Reinforcement on the Flexural Behavior of UHPC Plates

A series of flexural tests were performed in order to investigate the effect of steel fiber reinforcement (SFR) in textile‐reinforced concrete (TRC) plates. Some of the specimens were reinforced only with textile, some of them only with fibers, and some of them were provided with both textile and fiber reinforcement. The concrete matrix was a self‐developed ultrahigh performance concrete (UHPC) mixture with a compression strength over 160 MPa. The tensile strength of the used textiles was around 1500 MPa for glass fiber textile and over 3000 MPa for carbon fiber textile. In case of fiber reinforcement, the concrete was reinforced with 2 vol% of 15 mm long and 0.2 mm diameter plain high strength steel fibers. The dimensions of the rectangular plate test specimens were 700 × 150 × 30 mm. The plate specimens were tested in a symmetric four‐point bending setup with a universal testing machine. The tests were monitored using a photogrammetric measurement system with digital image correlation (DIC). The paper presents and evaluates the test results, analyses the crack patterns and crack development, and compares the failure modes. The results showed a general advantageous mechanical behavior of specimens reinforced with the combination of fibers and textiles in comparison to the specimens reinforced with only fiber or textile reinforcement.

Rectangular wave eddy current testing using for imaging of backside defects of steel plates

Accurate, easy, and fast inspection of defects on the backside of thick steel plates is essential for the maintenance of infrastructures. Low frequency eddy current testing (LF-ECT) is a promising method to detect defects of the backside of steel plates, with a thickness of approximately 10 mm. However, it is possible that the signal from the backside defect is smaller than that from the surface magnetic noise, causing difficulty identifying the backside defect. In this study, we propose a method to reduce the surface noise by employing a square wave inverter to generate a harmonic signal (rectangular wave ECT, or RECT), and the result demonstrates that the surface noise is successfully reduced using the harmonic signal.

An Improved Fuzzy Logic Control Method for Path Tracking of an Autonomous Vehicle

Highlights This study focused on the path tracking accuracy of a two-wheel steering, two-wheel drive autonomous vehicle. An improved fuzzy logic control method (IFM) was designed to control the steering angle of the front wheels. The IFM was better than traditional pure pursuit and fuzzy logic control methods for automatic path tracking. Abstract. This article presents a path-tracking algorithm based on an improved fuzzy logic control method (IFM) that generates optimal steering angles for an autonomous wheeled vehicle to track a sequence of waypoints. The path-tracking algorithm was designed to focus on the vehicle performance, including tracking accuracy, stability, and convergence speed. A prototype vehicle with two-wheel steering and two-wheel drive (2WS-2WD) was developed as a test platform and equipped with a series of sensors for evaluating the IFM. In this study, we considered two variables, i.e., lateral deviation (d) and heading deviation (θ), as inputs for the control system. The output (δ) was the steering angle of the front wheels as controlled by an electric linear actuator. A maximum steering angle strategy was adopted for rapid convergence when the vehicle was far from the desired path or when the heading deviation was large. An update-line distance algorithm was used for finding the best turning time as the vehicle moved closer to the next waypoint. To validate the proposed algorithm, testing was performed to compare traditional pure pursuit (TPP), traditional fuzzy logic control method (TFM), and the IFM in tracking two types of paths (straight and rectangular). Traveling at 0.5 m s-1 and with a signal sampling period of 0.5 s, the prototype converged to the desired straight path from different initial states. When the vehicle reached a stable state, the steady-state error was between 5.0 and 6.5 cm with a mean of ≤6.0 cm. The settling distance in the straight path test was between 125.0 and 422.3 cm, and the convergence time was in the range of 11.5 to 16.0 s; the greater the initial deviation of the vehicle was, the greater the settling distance and settling time were. In the 15 m x 14 m rectangular path test, the overall mean error of the IFM was 14.4 cm when the initial lateral and heading deviations were 0, and the maximum deviation was 67.4 cm, which occurred at the corners. The test results show that the proposed IFM had better accuracy, stability, and convergence speed for path tracking when compared to the TPP and TFM algorithms.

Hardness, compressive strength and resilience of complete denture lining materials: an in situ study

ABSTRACT Objective The aim of this study was to evaluate the in situ hardness, compressive strength and resilience of soft lining materials used in total removable prostheses in different time intervals Methods total of 48 rectangular test specimens (10 x 3 x 2 mm) were fabricated of each of the polyvinylsiloxane-based soft liner (Mucopren Soft) and acrylic resin-based material (Trusoft), which were placed on total removable prostheses bases of 12 volunteers (n = 12). The hardness (Shore A), compressive strength (in MPa) and resilience (in Kgf/cm2) were evaluated in different time intervals: 0, 7, 30 and 60 days, at three different locations of the specimens surface. Results The two-way ANOVA and Tukey test showed that the polyvinylsiloxane-based soft liner presented higher hardness values (p = 0.0113) and higher compressive strength (p=0.0252) than the acrylic resin-based material at immediate and 7 days evaluations. The polyvinylsiloxane-based soft liner presented higher resilience values than the acrylic resin-based material at all times (p = 0.0133). Hardness and compressive strength were similar for both materials at 30 and 60 days evaluations. Conclusions For both materials,there was a tendency for an increase of hardness, compressive strength and resilience over time, influenced by the composition of the tissue conditioner. The polyvinylsiloxane-based soft liner presented higher hardness, compressive strength and resilience than the acrylic resin-based material, specially considering a long-term evaluation up to 60 days.

Influence of Weather on Hardness and Surface Roughness of Maxillofacial Elastomeric Materials

The purpose of this study was to assess the influence of hot and dry weather on the hardness and surface roughness of four different maxillofacial silicone elastomeric materials (MFSEM) including two room-temperature vulcanized (RTV) and two high-temperature vulcanized (HTV) materials. Eighty test specimens were fabricated according to the manufacturer's instructions into rectangular test specimens. The hardness and surface roughness were tested, after 6 months of exposure to natural hot and dry weather. The hardness was measured through the International Rubber Hardness Degree (IRHD) scale using an automated hardness tester. The surface roughness was measured using a novel 3D optical noncontact technique using a combination of a light sectioning microscope and a computer vision system. Statistical Package for Social Sciences software SPSS/version 24 was used for analysis and a comparison between two independent variables was done using an independent t test, while more than two variables were analyzed, F test (ANOVA) to be used followed by a post hoc test to determine the level of significance between every two groups. The hot and dry weather statistically influenced the hardness and surface roughness of MFSEM. Cosmesil M-511 showed the least hardness in test groups while A-2000 showed the hardest material (p < 0.05). A-2000 showed significant changes from rough in case of nonweathered to become smoother in weather followed by A-2186 (p < 0.05). Cosmesil M-511 showed the roughest material. Cosmesil M-511 showed the least hard MFSEM after outdoor weathering while A-2000, the highest and least material showed hardness and surface roughness, respectively. A-2000 had a high IRHD scale hardness. This makes this material more suitable for the replacement of ear and nose defects. Cosmesil M-511 is soft and easily adaptable material that makes the material more appropriate for the replacement of small facial defect with undercut area to be easily inserted and removed. Whilst A-2000 is smoother and finer in test specimens after weathering, Cosmesil M-511 became rougher after weathering.

MELTING CHARACTERISTICS OF CAPSULATED PHASE CHANGE MATERIALS

An experimental and computational investigation studied phase change material melting in a cylindrical capsule with PCM. The capsule is placed horizontally in a rectangular test section, where it is insulated from all sides’ wall except the front one. The PCM capsule is heated by passing hot water from downward to upward with different inlet mean water temperatures (327.9, 333.7, 338 and 343) K, different velocities, varied thermal conductivities of capsule material wall (copper, iron, pyrex-glass, and polyethylene), and PCM. Experiment during melting inside a pyrex-glass capsule was performed and compared with prediction analysis by using CFD ANSYS 2019 R2. Image processing of melting photographs along with melted time were used in comparison. The comparison between the liquid fraction and energy stored with time for lauric acid and paraffin wax was analyzed. PCM liquid fraction, temperature and energy stored measurements for lauric acid were assessed numerically. The results reveal for lauric acid that the total melting time was enhanced 43% for 4.6% increase in water mean inlet temperature, 18% for 500% increase in inlet water mean velocity, and 7% when used copper capsule wall. The results proved that the lauric acid charged with energy stored were 47% more than paraffin wax during the total melting time of it, and the effect of different water mean inlet temperatures was the main factor for the charging process to improve the PCM melting time.

Human activities outcomes on the composition of woody plant species of Ngarama Southern Forest Reserve in Kilwa District, Tanzania

Abstract. Jilala ZJ, Mwakalukwa EE, Chamshama SAO. 2019. Human activities outcomes on the composition of woody plant species of Ngarama Southern Forest Reserve in Kilwa District, Tanzania. Asian J Ethnobiol 2: 108-118. This study evaluated the effects of human activities on the composition of woody plant species of the Ngarama Southern Forest Reserve (NSFR) in Kilwa District, Tanzania. Vegetation research was conducted in 40 systematically arranged rectangular test plots, aligned in five transepts over 2,070 ha forest. Information recorded in each plot included: species name, diameter at breast height (DBH), the height of selected timber species with a diameter ? 5 cm, and various indicators of human disturbance. Landsat TM and ETM+ images from 1995, 2000, and 2011 were used to locate and quantify the land cover change in the NSFR over the past 20 years. Inventory data was analyzed using Microsoft Excel and R software, while Landsat images were analyzed using the academic software ILWIS 3.0. About 126 plant species belonging to 34 families have been identified. Trees contributed 63% (28 families), and shrubs 37% (17 families). The Shannon-Wiener index and Simpson's diversity indices were 3.95 and 0.03, respectively. In addition, a mean stem density of 667 ± 19 stems ha-1 and a basal area of ??13.11 ± 0.34 m2 ha-1 were obtained. Twenty-three stumps (7 ± 3 ha-1 stems) with a mean baseline area of ??0.24 ± 0.09 m2 ha-1 stumps were removed, indicating ongoing anthropogenic disturbances in the forest. Other indicators of disturbance recorded were damage from fire (50%), paths / roads (13%), silage (8%), lumber/planks/pile harvesting (8%), cultivation (5%) and logging ( 8%). Although NSFR has a decent species richness and is well-diversified, there has been a consistently negative change in forest cover concerning low trunk density, average tree height, average DBH, and basal area, indicative of anthropogenic disturbance. Conservation measures are recommended to improve governance and accountability regarding accountability for intensive forest resource management.

Design, Fabrication and Testing of Smoke Wind Tunnel

Flow visualization is the direct observation of fluid flow. Moving fluids form complex patterns and understanding and visualizing those patterns is an important aspect in aerospace industry. The previously existing research and results were taken into consideration for design parameters and calculation for dimensions of various parts of the wind tunnel. Design calculations allow wind velocities in the range of 1-3 m/s at the test section. The design includes a rectangular test section of 0.06m x 0.30m cross-section for accommodation of test object of width 0.06m. The design was made in SolidWorks and was fabricated with basic materials like plywood and acrylic sheets. PC cabinet fans were used for flow circulation. Liquid wax is utilized for the purpose of smoke generation and rubber and PVC pipes were utilized for smoke containment and delivery system. Profiles that were used for testing included cylinder, sphere, cuboid, NACA airfoils and flat plate.