Effects of Orchard Characteristics and Operator Performance on Harvesting Rate of a Mechanical Sweet Cherry Harvester

A model was developed to simulate sweet cherry harvesting with a mirrored-pair mechanical harvest system that removes fruit by transferring vibrational energy to tree limbs through an impactor. Six orchard characteristic variables (ST – tree spacing; SR – row spacing; NT – number of trees per row; NR – number of rows; NTB – number of branches per tree; and WTF – total weight of fruit per tree) and three harvester/operator characteristic variables (vH – forward speed of harvester, tIP – time to position impactor on actuation point, and tPS – shaking time per actuation point) were the main inputs to the model. Total harvest time (tTH) and harvesting rate were the two output variables of the model. Harvesting rate was evaluated with three different measures: time rate of area coverage (RAC), time rate of tree coverage (RTC), and time rate of fruit removal by weight (RFR). The model was validated with field data, showing very close predictions with modeling efficiencies of 99%, 86%, 82% and 84% respectively for tTH, RAC, RTC, and RFR. Local sensitivity analysis was conducted varying the input variables in five different levels in order to observe their effect on the output variables. A global sensitivity analysis was also performed to identify input variables with significant effects on the output variables. Data from a complete factorial experiment with three levels of input variables in 19,683 combinations was used to perform the global sensitivity analysis. . It was revealed that ST and SR only affected RAC by defining the unit area occupied by a single tree. NT and NR only affected tTH by determining the number of trees to be harvested, but had no effect on harvesting rate. NTB greatly affected harvesting time and all measures of harvesting rate, and was identified as the most important variable. WTF only affected RFR by determining how much fruit is removed in a single shaking event. Of the harvester/operator variables, tIP affected all the outputs the most whereas vH affected none. Except for RAC, which was least affected by SR, tPS had the least effect amid all the significant input variables. These results provide explanation for achieving different harvesting rates in different orchard settings, and can be used to optimize orchard characteristics and adjust operator behaviors for improved performance in mechanical sweet cherry harvesting

Computer attitude, and the impact of personal characteristics and information and communication technology adoption patterns on performance of teaching faculty in higher education in Ghana, West Africa

This study examined computer attitude, and the impact of personal characteristics and ICT adoption patterns on performance of multidisciplinary teaching faculty in three public universities in Ghana. A cross-sectional research of mixed methods was applied in collecting data and information. Quantitative data from 164 respondents were analyzed using descriptive, multivariate analysis of MANOVA and simultaneous multiple linear regression statistics. Findings show high and positive computer attitude with affective dominating usefulness, behavior and control factors. Evidence of differential ICT adoption thresholds represented by computer purchase, general use, teaching, and research is observed. Overall ICT-based performance of the teaching faculty is modest. Significant variability in mean differences is reported across ICT performance factor levels on age and academic discipline, but not on gender and professional status. Independently, laggards predicted overall high statistically significant impact on ICT performance at 52% (p \u3c .01). All other significant predictors fall within regression coefficients of 17 and 38% (p \u3c.01 and .05 levels). Reasons, incentives and barriers to ICT integration were examined and reported together with special computer proficiency levels. Inclusive development is a palpable opportunity and the best practices are those supported holistically for their impact. Strategies for practice and further studies into adoption and performance behaviors that could ultimately influence investment, personal, professional, and overall growth of ICT in higher education are recommended

The Effect of the Growth Condition on the Properties of the New Material Sn3Sb2S6 Thin Films

Sulfosalt Sn3Sb2S6 material was synthesised by the horizontal Bridgman method. X-rays diffraction analysis of the powder showed that only homogenous Sn3Sb2S6 phase is present in the ingot. Sn3Sb2S6 thin films were deposited by a single source vacuum thermal evaporation with different thicknesses on glass substrates. The optical and structural properties of the films were studied as a function of thicknesses and temperature substrates. It is interest to note that Sn3Sb2S6 films exhibit polycrystalline structures along (416) preferred plane without heating the substrates. In addition, we note that as the thickness increases from 150 nm to 430 nm the average grain size increases from 190 to 350 °A. The samples have direct bandgap energies of 1.5 - 1.75 eV. Furthermore, we found that the absorption coefficient in all cases reached 104 cm−1. So, Sulfosalt Sn3Sb2S6 thin films could be used as a potential candidate in may technological applications such as photovoltaic solar cell

Open circuit fault diagnosis for a five-level neutral point clamped inverter in a grid-connected photovoltaic system with hybrid energy storage system

Introduction. Recently, the number of high and medium voltage applications has increased dramatically. The connection between these different applications requires series-parallel combinations of power semiconductors. Multilevel converter topologies provide major advantages to these applications. In this paper, a grid-connected photovoltaic system with a hybrid energy storage system using a five-level neutral point clamped inverter is studied. Although the multilevel inverter has many advantages over the two-level inverter, it has a high probability of experiencing an open circuit fault. In this context, the five-level inverter has 24 controllable switches, one of which may experience an open circuit fault at any time. Therefore, it plays an important part in the reliability and robustness of the whole system. The novelty of this paper presents an approach to accurately detect the open circuit fault in all insulated gate bipolar transistors of a five-level neutral point clamped inverter in a photovoltaic power generation application with a hybrid energy storage system. Purpose. Before using fault-tolerant control to ensure service continuity, fault diagnosis techniques must first be used, which are the crucial phase of reliability. Methods. A detection method based on the maximum and minimum error values is proposed. These errors are calculated using the expected and measured line-to-line pole voltages. Results. The open circuit fault detection method is implemented using MATLAB/Simulink. Simulation results showed the accuracy of detecting the open circuit fault in all insulated gate bipolar transistors in a short time. Moreover, this method is adaptable to several applications and is also robust to transient regimes imposed by solar irradiation and load variations.Вступ. Останнім часом різко зросла кількість застосувань високої та середньої напруги. З’єднання між цими різними використаннями вимагає послідовно-паралельних комбінацій силових напівпровідників. Топології багаторівневих перетворювачів надають цим додаткам великі переваги. У цій статті вивчається фотоелектрична система, підключена до мережі, з гібридною системою зберігання енергії, яка використовує п’ятирівневий інвертор із фіксуванням нейтральної точки. Хоча багаторівневий інвертор має багато переваг, порівняно з дворівневим інвертором, він має високу ймовірність виникнення обриву кола. У зв’язку з цим п’ятирівневий інвертор має 24 керовані перемикачі, один з яких будь-якої миті може зіткнутися з обривом кола. Таким чином, він відіграє важливу роль у надійності та стійкості всієї системи. Новизна цієї статті являє собою підхід до точного виявлення несправності розімкнутого кола у всіх біполярних транзисторах із ізольованим затвором п’ятирівневого інвертора з фіксуванням нейтральної точки у фотоелектричних додатках для вироблення електроенергії з гібридною системою зберігання енергії. Мета. Перш ніж використовувати відмовостійкий контроль для забезпечення безперервності обслуговування, необхідно спочатку використовувати методи діагностики несправностей, які є вирішальним етапом надійності. Методи. Запропоновано метод виявлення, заснований на максимальному та мінімальному значеннях помилок. Ці помилки розраховуються з використанням очікуваних та виміряних міжфазних напруг на полюсах. Результати. Метод виявлення обриву кола реалізовано з використанням MATLAB/Simulink. Результати моделювання показали точність виявлення обриву кола у всіх біполярних транзисторах із ізольованим затвором за короткий час. Більш того, цей метод адаптується до кількох застосувань, а також стійкий до перехідних режимів, викликаних сонячним випромінюванням та змінами навантаження

Participatory Approach to Common Use Grazing Management in Dry Area Developing Countries

Key points 1. Range restoration technology is available but useless when not followed by management. 2. Institutional mechanisms for grazing management are needed for communal range. 3. Community participatory approaches help pastoralists better manage rangeland grazing

Determinants of low birth weight in the Lower Manya Krobo Municipality of the Eastern region of Ghana

Background: Low birth weight refers to new borns weighting less than 2.5 kg at birth. In November 2017, the WHO reported a global prevalence of 15.5% with 96.5% of these cases happening in developing countries. Whilst this is a global canker, the risk factors differ from locality to locality.  This study aims at determining which maternal factors explains low birth weight baby delivery in the Lower Manya Krobo Municipality.Methods: The chi-square test for independence was used to test for independence. The binary logistic model is fitted for the associated factors. The receiver operating characteristic (ROC) is used to classify unbiased estimators.Results: ANC (yes β= -2.769 sig.=0.000); Alcohol (none β=-1.479 sig.=0.000, occasionally β= −2.043 sig.=0.000); Age (<20years β=0.178 sig. =0.676, 20 to 25years β= -1.487 sig.=0.000, 26 to 30 β= -0.941 sig.=0.086); Education level (None β=2.778 sig. =0.000, primary β=3.090 sig.=0.000, JHS β=1.913 sig.=0.002, SHS/Secondary β=1.951 sig.=0.000); Exposure to Heat (Yes β=4.507 sig.=0.000). AUC education=0.67, 95% CI=0.6,0.7 and AUC Exposure to heat=0.73, 95% CI=0.68,0.77 of low birth weight.Conclusions: Social status was not significant factor. Mothers exposed to heat had the highest risk (odds=90 times). Adolescent mothers stand high risk with odds 1.195. Mothers who attended antenatal clinics were at 94% less likelihood. Mild drinkers had lesser risk compared to no and heavy drinkers. Mothers with primary education (odds=21 times) were the riskiest compared to mothers with tertiary education. This differs from researches where no education mothers were riskiest. Only mother’s exposure to heat was found to be fairly good unbiased estimators

Methods for the evaluation of forage legumes, grasses and fodder trees for use as livestock feed

Forage plant evaluation is carried out by many institutions throughout sub-Saharan Africa. However, the approach adopted at various locations varies. This manual outlines standard evaluation methodology, which will enable researchers throughout the region to obtain meaningful results from their forage plant evaluation. This document is based on experience from the forage evaluation programme at ILCA, Kaduna. The first section deals with methodology for initial evaluation, including suitable methodology for small-plot evaluation trials and larger multi-locational trials. The second section covers methodology suitable for further evaluation of accessions identified in the initial evaluation