123 research outputs found

    Employee Turnover In The Small Business: Practical Insights From Urban Child Care Centers

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    This paper investigates the claims of alarming turnover rates in the childcare work force (as claimed by the Center for the Childcare workforce) in the context of organizational literature.  Data collected from 70 childcare centers of New York City partially support the traditional claim that behavioral variables (such as job satisfaction and commitment) explain variations in turnover rate.  Additionally, it claims that negative work outcomes (or work itself could be cause of voluntary turnover) in this instance, the behavior problem, discipline problem, funding uncertainty and the like may be included in any deterministic model of employee turnover.  Finally, this study did not find overwhelming evidence supporting the alarming rate of turnover in the childcare centers

    Organizational Profile, HR Practices And The Perceived Quality And Performance Of Small Businesses: Empirical Highlights From The Urban Child Care Centers

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    This paper examines the relationships among the organizational profile, the human resource practices, and the quality and profitability of private childcare centers of a large metropolis.  Organizational profile variables included: size (measured in terms of total FTE employees), age (measured in terms of number of years in service), HR practices included: empowerment and enrichment strategies, benefits, grievances, affirmative action, promotion, supervision, participation in decision-making, and the like. Quality is a variable reflecting the perception of service relative to the population of similar centers.  It also includes the application of quality concepts such as benchmarking, and continuous improvement. The organizational performance includes such variables as perceived relative profitability, annual revenues, and behavioral measures of employees (i.e., motivation, morale, commitment, trust, turnover, and job satisfaction).  Data was collected as a pilot project in 2001 through a mail questionnaire as well as through personal interviews of the owners/directors of 70 (out of 200 selected) private childcare centers of New York City. The findings of correlation and the regression analyses support a number of illustrative hypotheses pertaining to the association among the selected variables.  The paper interpreted the finding in the light of existing organizational theories and concludes with a list of highlights (imperatives) for the owner/directors of urban child care centers

    Cyber attacks and faults discrimination in intelligent electronic device-based energy management systems

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    Intelligent electronic devices (IEDs) along with advanced information and communication technology (ICT)-based networks are emerging in the legacy power grid to obtain real-time system states and provide the energy management system (EMS) with wide-area monitoring and advanced control capabilities. Cyber attackers can inject malicious data into the EMS to mislead the state estimation process and disrupt operations or initiate blackouts. A machine learning algorithm (MLA)-based approach is presented in this paper to detect false data injection attacks (FDIAs) in an IED-based EMS. In addition, stealthy construction of FDIAs and their impact on the detection rate of MLAs are analyzed. Furthermore, the impacts of natural disturbances such as faults on the system are considered, and the research work is extended to distinguish between cyber attacks and faults by using state-of-the-art MLAs. In this paper, state-of-the-art MLAs such as Random Forest, OneR, Naive Bayes, SVM, and AdaBoost are used as detection classifiers, and performance parameters such as detection rate, false positive rate, precision, recall, and f-measure are analyzed for different case scenarios on the IEEE benchmark 14-bus system. The experimental results are validated using real-time load flow data from the New York Independent System Operator (NYISO)

    Numerical Prediction of Laminar Characteristics of Fluid Flow and Heat Transfer in Finned-Tube Heat Exchangers

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    This study is performed to determine the characteristics of fin and tube heat exchanger for the plain and wavy fin configurations considering in lined and staggered tube arrangements for laminar flow regime. This analysis has been conducted using Commercial Computational Fluid Dynamics Code ANSYS CFX-11. The results are expressed in terms of friction factor (f) and the Colburn factor (j) and efficiency index (j/f).The code was validated by comparing the results obtained with the previously investigated experimental data. The effects of different geometrical parameter such as Longitudinal pitch, Transverse Pitch, Fin Pitch, Wavy angle on the heat transfer and the pressure drop were investigated. This study reveals that the flow distinction between plain and wavy fin has a profound influence on the heat transfer and pressure drop performance. It was observed that, increasing the longitudinal and transverse pitch causes a decrease in the thermal and hydraulic performance of the heat exchanger for low Reynolds Number problem. The result for the fin pitch study indicated that decrease in the fin pitch causes a decrease in both heat transfer and friction characteristics significantly. Keywords: Friction factor, Colburn factor, Efficiency index, longitudinal pitch, transverse pitch, fin pitch

    Selection of cemented carbide turning tools using EMF and optimization criteria

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    Tool life and quality of surface finish of the workpiece influence production rate and production cost. Cemented carbide tools have found wide application in the production arena of Bangladesh. In the absence of any testing facility in the country for the selection of cost-effective tools, poor quality carbide tools are frequently imported. A testing method and a selection criteria were developed for testing carbide tools of different shapes and sizes and for selecting the most cost-effective tool. For each tool cutting tests were performed to generate tool life data under different cutting conditions. Mild steel served as the work material. The relationship between tool life and cutting speed was developed using a curve-fitting software on a PC. From these relationships the values of the constants of the Taylor’s equation were determined. The cost equation was then derived for each tool for a given amount of work in a cutting speed range. Finally, the most cost-effective tool was selected on the basis of the relative location of the cost curves of the tools tested

    Systemic delivery of siRNA nanoparticles targeting RRM2 suppresses head and neck tumor growth

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    Systemic delivery of siRNA to solid tumors remains challenging. In this study, we investigated the systemic delivery of a siRNA nanoparticle targeting ribonucleotide reductase subunit M2 (RRM2), and evaluated its intratumoral kinetics, efficacy and mechanism of action. Knockdown of RRM2 by an RNAi mechanism strongly inhibited cell growth in head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC) cell lines. In a mouse xenograft model of HNSCC, a single intravenous injection led to the accumulation of intact nanoparticles in the tumor that disassembled over a period of at least 3 days, leading to target gene knockdown lasting at least 10 days. A four-dose schedule of siRNA nanoparticle delivering RRM2 siRNA targeted to HNSCC tumors significantly reduced tumor progression by suppressing cell proliferation and inducing apoptosis. These results show promise for the use of RRM2 siRNA-based therapy for HNSCC and possibly NSCLC

    Beneficial impacts of biochar as a potential feed additive in animal husbandry

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    In the last decade, biochar production and use have grown in popularity. Biochar is comparable to charcoal and activated charcoal because it is a pyrogenic carbonaceous matter made by pyrolyzing organic carbon-rich materials. There is a lack of research into the effects of adding biochar to animal feed. Based on the reviewed literature, including its impact on the adsorption of toxins, blood biochemistry, feed conversion rate, digestion, meat quality, and greenhouse gas emissions, adding biochar to the diet of farm animals is a good idea. This study compiles the most important research on biochar's potential as a supplement to the diets of ruminants (including cows and goats), swine, poultry, and aquatic organisms like fish. Biochar supplementation improves animal growth, haematological profiles, meat, milk and egg yield, resistance to illnesses (especially gut pathogenic bacteria), and reduced ruminant methane emission. Biochar's strong sorption capacity also helps efficiently remove contaminants and poisons from the animals' bodies and the farm surroundings where they are raised. Animal farmers are predicted to make greater use of biochar in the future. Biochar could potentially be of value in the healthcare and human health fields; hence research into this area is encouraged. The present review highlights the potential benefits of biochar as an additive to animal feed and demonstrates how, when combined with other environmentally friendly practices, biochar feeding can extend the longevity of animal husbandry

    Fast and Scalable Synthesis of LiNi0.5Mn1.5O4 Cathode by Sol-Gel-Assisted Microwave Sintering

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    High-voltage spinel LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material for high-energy-density and high-power-density lithium-ion batteries (LIBs). The high cost of the currently available LIBs needs to be addressed urgently for wide application in the transport sector (electric vehicles, buses) and large-scale energy storage systems (ESS). Of significance, herein, novel fast and scalable microwave-assisted synthesis of LNMO is reported, which leads to a production cost cut. X-ray diffraction (XRD) analysis confirms the formation of the desired phase with high crystallinity. Field emission scanning (FE-SEM) and transmission electron microscopy (TEM) analyses indicate that the synthesized phase is of nanometric size (50–150 nm) due to an extremely short sintering time (20 min). The material synthesized at 750 °C shows a higher initial discharge capacity (130 mA h g−1) than that synthesized at 650 °C (115 mA h g−1). The materials heat treated at higher temperatures show better electrochemical performance in terms of initial capacity, rate capability, and improved cycling. The improved electrochemical performance of LNMO at 750 °C is attributed to the formation of a stable crystal structure, low charge transfer resistance at the electrode/electrolyte interface, high electrical conductivity due to the presence of a disorder structure, and improved ionic diffusivity.This publication was made possible by NPRP Grant # NPRP11S-1225-170128 from the Qatar National Research Fund (a member of the Qatar Foundation). Statements made herein are solely the responsibility of the authors. The authors would like to acknowledge the technical support from Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA, and the Central Laboratory Unit (CLU), Qatar University, Doha, Qatar. The authors also acknowledge Core Labs. at Qatar Environment and Energy Research Institute (QEERI), HBKU, Qatar, for FE?SEM and TEM analysis. Open Access funding provided by the Qatar National Library.Scopu

    Cinnamon as a Potential Feed Additive: Beneficial Effects on Poultry Health and Production Performances – An Update

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    According to the Food and Agricultural Organization, global poultry output increased from approximately 115 million tons in 2016 to around 136 million tons in 2023. Poultry production has increased significantly with the dramatic uptick in meat and egg demand. Feed accounts for between 65 and 70 percent of total production costs, making it the largest chicken industry expense. This is why it's important to maximize the transformation of poultry feed into feed with a high biological value while taking as many steps as possible to protect feed quality and reduce feed costs. The use of feed additives in poultry feed has recently gained popularity and has been essential to increase feed efficiency and growth rate, which typically leads to reduced costs. The meat's texture, consistency, and nutritional content are all improved, and its shelf life is lengthened as a bonus. Feed additives are a fantastic tool for boosting a poultry farm's bottom line. For example, cinnamon (Cinnamomum verum) is often used as a traditional feed supplement. Rather than antibiotics, the poultry industry could benefit from using cinnamon as a natural antibiotic replacement, which would benefit animal welfare, consumer health, and the bottom line. The performance index, feed intake, FCE performance, and weight growth of poultry can all be improved by including cinnamon in the feed at varied concentrations. The digestive health and intestinal microbial population of hens are enhanced by a diet containing bioactive components of cinnamon. Cinnamon essential oils' popularity stems from their many valuable features, such as their ability to increase gastric enzyme synthesis and other biofunctional benefits. This review focuses on the possible advantages of cinnamon as a natural feed supplement for chickens, particularly about their intestinal microbiota, blood chemistry, nutrient absorption, gene expression, and immunology
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