Effect of length-to-diameter ratio on axial velocity and hydrodynamic entrance length in air-water two-phase flow in vertical pipes

Peer reviewedPublisher PD

Synthesis, Characterization and study biologicalactivity of several 1-cyclopentene-1,2-dicarboxylimidyl Containing oxadiazole and Benzothiazole

In this work involved prepared of several new 1-cyclopentene-1,2-dicarboxylimide linked to oxadiazole and benzothiazole moiety were synthesized by two steps: The first step 2-amino-substituted-1,3,4-oxadiazoles and substituted-2-aminobenzothiazole were reaction with 1-cyclopentene-1,2-dicarboxyl anhydride producing N-( 5- substituted-1,3,4-oxadiazole-2-yl)-1-cyclopentene-1,2-dicarboxyl amic acids and N-(Substitutedbenzothiazole-2-yl)-1-cyclopentene-1,2-dicarboxyl amic acids which in turn were dehydrated in the second step via fusion method to afford he desirable N-(5-substituted-1,3,4-oxadiazole-2-yl)-1-cyclopentene-1,2-dicarboxylimides and N-(Substituted benzothiazole-2-yl)1-cyclopentene-1,2-dicarboxylimides respectively. Structures of the prepared compounds were characterized by depending on FTIR, U.V spectral data which were in agreement with the proposed ones. Finally antibacterial activity of some of the prepared new cyclic imides were studied by two types of bacteria and the results showed that the most of the tested imides posses good biological activity against these bacteria

Development and Evaluation of a Combined Castor Seed Roaster-Oil Expeller

This study evaluated optimal process parameters for mechanical oil expression from castor seeds after designing a castor seed roaster-expeller. The effect of input variables (Moisture Content at 6, 7, 8, 9 and 10% db; Roasting Temperature at 80, 90, 100,110 and 120oC and Applied Pressure at 15, 20, 25, 30 and 35 MPa) on the oil yield, expression efficiency, expression loss and energy used were determined using Central Composite Design in Response Surface Methodology for the optimization and modelling. Analysis of Variance was employed to determine the level of significance (P≤ 0.05). The optimum expression efficiency, expression loss and minimum energy used were 72.86%, 0.63% and 584.19 Watts obtained at experimental conditions of 15.00 MPa applied pressure, 6% moisture content and 85.52°C heating temperature respectively. The R2 values of the developed models ranged from 0.813 to 0.982 at 95% confidence level. The developed combined castor seed roaster-oil expeller was found to be efficient and developed models showed adequate prediction with good relationships between dependent and independent variables. Keywords: castor seed, oil extraction, modeling, optimization DOI: 10.7176/ISDE/11-1-07 Publication date: January 31st 2020

Thermal Properties and Energy Utilization of Cassava Meal in Conductive Rotary Drying

Abstract In this study the thermal properties and drying behaviour of cassava meal in a conductive rotary dryer was investigated. Cassava flour and gelatinized gari were produced at drying temperatures of 70°C and 90°C, respectively. The activation energy of cassava meal was 49.52 kJ/mol, and the effective moisture diffusivity, thermal conductivity and heat capacity increased with temperature from 1.74x10 -10 to 4.51x10 -10 m 2 /s, 0.329 to 0.344 W/m°C and 1.804 to 1.901 kJ/kg°C, respectively. With increase in bulk density of cassava meal from 379.50±2.55 to 464.79±30.38 kg/m 3 , thermal diffusivity and specific energy consumption decreased from 4.81x10 -7 to 3.89x10 -7 m 2 /s and 618.88 to 456 kJ/kg, respectively. The thermal efficiency of the dryer was greater than 31% for both cassava flour and gari. Compared with previous works, performance of the conductive rotary dryer was satisfactory and upgrade of its design will make it suitable for application in the cassava processing industry

Unit root modeling for trending stock market series

In this paper, we examine how the unit root for stock market series should be modeled. We employ the Narayan and Liu (2015) trend GARCH-based unit root and its variants in order to more carefully capture the inherent statistical behavior of the series. We utilize daily, weekly and monthly data covering nineteen countries across the regions of America, Asia and Europe. We find that the nature of data frequency matters for unit root testing when dealing with stock market data. Our evidence also suggests that stock market data is better modeled in the presence of structural breaks, conditional heteroscedasticity and time trend

National inventory of emergency departments in Singapore

Background: Emergency departments (EDs) are the basic units of emergency care. We performed a national inventory of all Singapore EDs and describe their characteristics and capabilities. Methods: Singapore EDs accessible to the general public 24/7 were surveyed using the National ED Inventories instrument ( http://www.emnet-nedi.org). ED staff members were asked about ED characteristics with reference to calendar year 2007. Results: Fourteen EDs participated (100% response). All EDs were located in hospitals, and most (92%) were independent departments. One was a psychiatric ED; the rest were general EDs. Among general EDs, all had a contiguous layout, with medical and surgical care provided in one area. All but two EDs saw both adults and children; one ED was adult-only, and the other saw only children. Six were in the public sector and seven in private health-care institutions, with public EDs seeing the majority (78%) of ED patients. Each private ED had an annual patient census of 60,000. They received 98% of ambulances and had an inpatient admission rate of 30%. Two public EDs reported being overcapacity; no private EDs did. For both public and private EDs, availability of consultant resources in EDs was high, while technological resources varied. Conclusion: Characteristics and capabilities of Singapore EDs varied and were largely dependent on whether they are in public or private hospitals. This initial inventory establishes a benchmark to further monitor the development of emergency care in Singapore

Photovoltaic Thermal /Solar (PVT) Collector (PVT) System Based On Fluid Absorber Design : A Review

Photovoltaic thermal (PVT) is a hybrid system,which incorporates both thermal and electrical energy generations.PVT can be used as a cooling system for the PV system in order to enhance the electrical energy efficiency and at the same time,produce thermal energy, which can be used in other applications.There are various types of PVT collectors including water or air,based on the fluid used in the PVT system.This paper aims to review the advancement and progress in the field of PVT collector based on water fluid.The review investigated various research articles by analysing their proposed designs of PVT collector and absorber.The shortcomings and drawbacks of the available PVT collector are presented in order to show the research gap in the field of PVT collector-based water.Different PVT collectors and absorbers configurations are presented and discussed.The study concludes that water-based PVT are widely used and produce improved efficiency as compared to the air-based PVT

Thermal Analysis of Horizontal Earth-Air Heat Exchangers in A Subtropical Climate: An Experimental Study

Data availability statement: The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.Copyright © 2022 Lattieff, Atiya, Lateef, Dulaimi, Jweeg, Abed, Mahdi and Talebizadehsardari. The earth-air heat exchanger (EHX) has a promising potential to passively save the energy consumption of traditional air conditioning systems while maintaining a high degree of indoor comfort. The use of EHX systems for air conditioning in commercial and industrial settings offers several environmental benefits and is capable of operating in both standalone and hybrid modes. This study tests the performance and effectiveness of an EHX design in a sandy soil area in Baghdad, Iraq. The area has a climate of the subtropical semi-humid type. Ambient air temperatures and soil temperatures were recorded throughout the months of 2021. During the months of January and June, the temperatures of the inlet and outflow air at varying air velocities were monitored concurrently in 10-min increments at each location. Further numerical and thermodynamical analyses of the measurements were conducted to reveal the influencing performance parameters. The highest temperature rises of air between the input and exit sections were determined as 12.3°C (January) and 17.2°C (June). It is found that the maximum values of effectiveness are 0.80 and 0.81, while coefficients of performance are 1.6 and 1.8 for January and June, respectively. It is also found that the EHX shows good functionality and effectiveness, with potential energy savings for equipment for cooling and heating under different weather conditions