A novel geothermal heat pump (GHP) system with an integrated low- to moderate-temperature salt hydrate phase change material (PCM) storage tank for buildings in cold climates is proposed in this study. The purpose of the PCM storage tank is to dampen peak heating loads and to remove annual ground thermal load imbalances on the ground heat exchanger (GHX) to assist in achieving an optimally-sized GHX. As heat is extracted from the closed-loop system by heat pumps in heating mode, a significant portion of this heat is used to solidify a salt hydrate PCM. This heat of fusion is later released back into the heat transfer fluid, storing it in the PCM tank and GHX for later diurnal and seasonal use. To examine the merits of the proposed concept, electric utility meter data on 15-minute time intervals were mined from an actual apartment building and used to estimate space heating, cooling, and hot water heating loads. Those data were used in an hourly, dynamic 20-year life-cycle simulation model in TRNSYS to design an optimum combination of GHX and PCM storage, where each component was sized to balance the annual ground thermal loads. The system simulation results show significant potential for GHX size reduction with a PCM storage tank, but the system is quite sensitive to the PCM melt temperature due to significant hysteretic nature of the salt hydrate PCM heating and cooling curves. We also find that there is no unique optimum unless other factors are considered such as installation cost and physical constraints; many combinations of GHX size and PCM mass are capable of achieving the design goal with similar annual electric energy consumption. For the cases examined here, a PCM melt temperature of 27 °C yields the most favorable economic results, and a preliminary economic analysis suggests that with typical drilling cost and PCM tank cost values, the GHX size can be reduced by over 50 %.

The present study endeavors to explore the dynamic causal relationship between economic growth and financial development in Kuwait, covering the time span between 1991 and 2017. Based on the objective of presenting robust results in relation to the research focus, a combination of time and frequency-domain methodologies has been applied. Using the Toda–Yamamoto and the Fourier Toda–Yamamoto time-domain techniques, no causal direction is found through the former test, while the causality flowing from financial development to economic growth is demonstrated by the latter. Nevertheless, the spectral causality test developed by Breitung and Candelon [(2006). “Testing for short- and long-run causality: A frequency-domain approach.” Journal of Econometrics 132 (2): 363–378. https://doi.org/10.1016/j.jeconom.2005.02.004] gives a more thorough overview of the dynamic causal relationships because it allows the temporary and permanent movements in the linkages between variables to be differentiated. The findings show proof of a bidirectional causality between financial development and economic growth. Our findings highlight the emphasis on covering the frequency causality to provide greater insight into the interrelationship between the variables under consideration.

Quality assurance and institutional accreditation in education is becoming of paramount importance. This study aims to assess the impacts of the accreditation process of the National Center for Quality Assurance and Accreditation (NCAAA) on the quality of education in one of private university in Libya. Methods: The research adopts a descriptive study design in University of Tripoli Alahlia (UTA) where an official accreditation process was completed by the NCQAA during 2017-2019. Data were collected using the self-study report that produced by the NCQAA accreditation committee during the accreditation process, and were retrieved in specific data collection sheet by one of the authors. Results: The NCQAA accreditation process that lasted about 4 years brought significant changes in the educational progressions and made the staff members more aware of quality issues in education. Our findings also reported significant improvements in the quality of education in the university. Conclusions: The process of NCQAA accreditation conducted in UTA has been positively improved the quality of education. Data from other institutions would also expressively increase the relevance and rationality of the study.

The metallurgical influence of niobium (Nb) on an annealed high manganese (Mn) steel is still an active issue of discussion between automobile companies and steel manufacturers. Some controversy exists in the literature concerning the influence of Nb solubility on microstructure and thereby on mechanical properties. The influence of Nb-solubility on microstructure of Fe30Mn alloy steel was investigated experimentally and by computational materials modeling. Nb was added in 0.05, 0.1, 0.2, 0.4, 0.6 and 1% additions and the alloy samples were annealed at 1200oC for 2, 5, 10, 30 and 60 minutes. The microstructure was investigated using an optical microscope, TEM and SEM-EDX and precipitates were chemically tested. Niobium solubility in Fe30Mn austenite was theoretically studied based on Gladman assumptions and was also examined by Thermo-Calc analysis. The result of this work is a comparison between the microstructure analysis and theoretical studies, and it has been found that Nb was soluble in Fe30Mn austenite phase and has had a solute drag effect where Nb(C,N) and NbN precipitates were seen and the effect was pinning effect 

Abstract

Cohesion is one of the most important characteristics of good translation. Having a good translation is not achieved unless this factor is carefully observed. We may find students who have good mastery of spelling, grammatical rules and the skill of speaking but have noticeable weaknesses of using cohesive devices when they translate literary prose texts from Arabic into English. This study tries to examine the use of cohesive devices by University students when they translate literary prose text from Arabic into English. Texts used as a tool or instrument of data collection were given to some students to translate. The participants, in their translations, depended on certain devices ignoring the others. The subjects disregarded completely some categories of cohesive devices, such as the class of possessive pronouns, comparative reference, ellipsis, and substitution. Students sometimes misused the items, such as what happened with ‘the’. Many students were unable to vary the language (expressions) they used to express their ideas. Students sometimes succeeded in achieving cohesiveness but sometimes failed. A number of students did not end the sentences they wrote and started new ones.

As businesses are spreading to different locations they require a strong 

and secure way of communication between the different offices. There 

are different services which require nonstop flow of traffic. The 

multimedia applications with voice and video needs more priority than 

other applications, as it is sensitive to delay. The MPLS (Multiprotocol 

Label Switching) based VPN (Virtual Private Network) can provide QoS 

(Quality of Service) features. This paper investigate on how DiffServ 

QoS Model parameters over MPLS VPNs environment can help the 

enterprise network customers to maintain the quality for their multimedia 

application usage in their network. To test our approach, a MPLS VPN 

Traffic Engineering approach was configured on two distinct enterprise 

businesses and MPLS VPN networking with and without DiffServ QoS 

parameters for voice, email and data were implemen