In this study, performance experiments and economic analysis of a horizontal ground source heat pump (GSHP) system have been performed. The horizontal GSHP system connected to a test room, Elazığ ...(38.41°N, 39.14°E), Turkey, was designed and constructed for space heating. The heating and cooling loads of the test room were 2.5 and 3.1
kW at design conditions, respectively. The performance was determined experimentally under real operational conditions. The experimental results were obtained from 7 November 2002 to 3 May 2003 in the heating season of 2002–2003. A detailed cost analysis was presented and payback periods when substituting for different local fuel/power sources were determined. The GSHP system was compared to conventional heating methods (electric resistance, fuel oil, liquid petrol gas, coal, oil and natural gas) in the economical analysis using an annualised life cycle cost method. It was shown that the GSHP system offers economic advantages over the mentioned first five conventional heating methods. However, it is not an economic alternative system to natural gas.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper reports a techno-economic comparison between a ground-coupled heat pump (GCHP) system and an air-coupled heat pump (ACHP) system. The systems connected to a test room in Firat University, ...Elazig (38.41°N, 39.14°E), Turkey, were designed and constructed for space cooling. The performances of the GCHP and the ACHP system were experimentally determined. The experimental results were obtained from June to September in cooling season of 2004. The average cooling performance coefficients (
COP
sys
) of the GCHP system for horizontal ground heat exchanger (HGHE) in the different trenches, at 1 and 2
m depths, were obtained to be 3.85 and 4.26, respectively and the
COP
sys
of the ACHP system was determined to be 3.17. The test results indicate that system parameters can have an important effect on performance, and that GCHP systems are economically preferable to ACHP systems for the purpose of space cooling.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper describes the applicability of artificial neural networks (ANNs) to predict performance of a horizontal ground-coupled heat pump (GCHP) system. Performance forecasting is the precondition ...for the optimal control and energy saving operation of heat pump systems. ANNs have been used in varied applications and they have been shown to be particularly useful in system modelling and system identification. In order to train the ANN, limited experimental measurements were used as training data and test data. In this study, in input layer, there are air temperature entering condenser unit and air temperature leaving condenser unit, and ground temperatures (1 and 2
m); coefficient of performance of system (COPS) is in output layer. The back propagation learning algorithm with three different variants, namely Levenberg–Marguardt (LM), Pola–Ribiere conjugate gradient (CGP), and scaled conjugate gradient (SCG), and tangent sigmoid transfer function were used in the network so that the best approach can find. The most suitable algorithm and neuron number in the hidden layer are found as LM with seven neurons. For this number level, after the training, it is found that Root-mean squared (RMS) value is 1%, and absolute fraction of variance (
R
2) value is 99.999% and coefficient of variation in percent (COV) value is 28.62%. It is concluded that, ANNs can be used for prediction of COPS as an accurate method in the systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this study, the cylindrical phase change storage tank linked to a solar powered heat pump system is investigated experimentally and theoretically. A simulation model defining the transient ...behaviour of the phase change unit was used. In the tank, the phase change material (PCM) is inside cylindrical tubes and the heat transfer fluid (HTF) flows parallel to it. The heat transfer problem of the model (treated as two-dimensional) was solved numerically by an enthalpy-based finite differences method and validated against experimental data. The experiments were performed from November to May in the heating seasons of 1992–1993 and 1993–1994 to measure both the mean temperature of water within the tank and the inlet and outlet water temperature of the tank. The experimentally obtained inlet water temperatures are also taken as inlet water temperature of the simulated model. Thus, theoretical temperature and stored heat energy distribution within the tank have been determined. Solar radiation and space heating loads for the heating seasons mentioned above are also presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The goal of this study is to reveal the effects of N
2
incorporation in DLC coatings in terms of carbon bond formation and to understand the tribological behavior of this coating by conducting ...thorough investigations on the coated substrates. This study reports the effects of diamond-like carbon (DLC) and nano-crystalline diamond (NCD) film on improving tribological behavior under harsh friction conditions. The film was deposited on AISI 1018 low-carbon steel alloy substrates cut from a piston ring of an internal combustion engine via electron cyclotron resonance plasma chemical vapor deposition (ECR-CVD) technique at bias voltage of − 600 V using methane (CH
4
) as carbon source and nitrogen (N
2
) to crystallize the carbon bonds in DLC/NCD form by varying the flow rates (CH
4
/N
2
plasma). The coated substrates were analyzed in terms of friction and wear (reciprocating friction-wear test module), surface morphology (SEM, AFM), chemical composition (EDX, XRD), hardness, surface roughness, and bond structure (Raman). The film deposited at 8 sccm of N
2
and 6.05 sccm of CH
4
depicted the maximum hardness (47 HRC) and minimum wear rate (6.35*10
–9
mm
3
/Nm) during the abrasion tests. It was evident that DLC/NCD film was deposited on the substrate according to related analyses and the DLC/NCD coating on the piston ring material provides considerable improvements on tribological performance leading to reduced fuel consumption, cleaner and more efficient fired engines.
•Evaluate feasibility of greenhouse heating by renewable energy sources.•Comparison of GSHP, biogas and solar energy in the greenhouse heating.•Greenhouse practices can be an alternative income ...generating source.
The interest in alternative or renewable energy sources for greenhouse heating is currently high, owing to the large heating loads and the relatively high price of fossil fuels. Important alternative sources of energy are solar collectors, heat pumps, biomass and cogeneration systems. This study experimentally investigates greenhouse heating by biogas, solar and ground energy in Elazig, Turkey climate conditions. The greenhouse (6m×4m×2.10m) heated by mentioned alternative energy sources was constructed, and then required heating load of the greenhouse was determined. For this purpose, biogas, solar and a ground source heat pump greenhouse heating system (BSGSHPGHS) with horizontal slinky ground heat exchanger was designed and set up. Experiments were conducted extensively during the winter period from November 2009 to March 2010. During the experiments, 2231.83l of gas production by biogas system is provided. The experiments that are required for the growth of many plants need temperature of 23°C, and conceivable success has been achieved in reaching this value by built systems. As a result, different energy sources have been successfully tested for greenhouse heating.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this study, the electromagnetic interference (EMI) and ultraviolet–infrared (UV–IR) shielding behavior of wool (WO) and cotton/elastane (CO/EL) nanocomposite fabrics have been investigated. The ...study aims to investigate the EMI and UV–IR shielding performance of the CO/EL and wool-based fabrics coated with carbon (C), graphite (Gr), and indium (In) nanocomposite layers. To produce nanocomposite fabric samples, these three materials were used in different compositions and the coating processes were carried out by electron cyclotron resonance (ECR) and thermal evaporation methods. Subsequently, the EMI and UV–IR measurements were performed for the coated fabric samples, and the results have been analyzed. In this study, it has been proven for the first time that the ECR coating method can be used for coating fabrics as a textile material. Finally, it is found that the C+Gr(grid filled)+In wool sample and the carbon-coated CO/EL sample have widely exhibited a significant positive effect on increasing the EMI shielding performance in the range of 18–43 and 12–18 GHz frequencies, respectively. In addition, the results show that the C+Gr(grid)+C-coated CO/EL fabric has significant potential to increase the UV–IR shielding performance.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, slinky (the slinky-loop configuration is also known as the coiled loop or spiral loop of flexible plastic pipe)type ground heat exchanger (GHE) was established for a solar-assisted ...ground source heat pump system. System modelling is performed with the data obtained from the experiment. Artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) are used in modelling. The slinky pipes have been laid horizontally and vertically in a ditch. The system coefficient of performance (COP
sys
) and the heat pump coefficient of performance (COP
hp
) have been calculated as 2.88 and 3.55, respectively, at horizontal slinky-type GHE, while COP
sys
and COP
hp
were calculated as 2.34 and 2.91, respectively, at vertical slinky-type GHE. The obtained results showed that the ANFIS is more successful than that of ANN for forecasting performance of a solar ground source heat pump system.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Introduction: Although bones are more flexible and have higher
shock absorption ability in childhood than in adulthood, bone fractures
are often seen in children who present to the emergency clinics
...after a trauma. This study was conducted to identify the pattern
and the rate of traumatic lower extremity fractures in children.
Methods: Files and X-rays of 485 patients aged under 18 years who
presented to the Emergency Department of the Tokat Gaziosmanpaşa
University Healthcare Research and Application Hospital after
a trauma were retrospectively reviewed. Data of 146 children who
presented with a trauma to the lower extremity were examined.
Fractures were assessed based on age groups, gender, etiology,
and the affected bone.
Results: Of the 146 children who presented with a trauma to the
lower extremity, 112 were male (77%) and 34 were female (23%).
Traumas had been mostly experienced in the summer, followed
by spring, autumn, and winter. The femur was the most commonly
affected bone among the fractures caused by a trauma (n=32,
33.33%). Single-bone fractures most commonly involved the femur,
followed by the tibia, the phalanx, and the metatarsal bones,
whereas double-bone fractures most commonly involved the tibia
and the fibula. Falling down was the major cause of trauma
Discussion and Conclusion: We believe that the results of our
study will help to better understand the occurrence of traumatic
lower extremity fractures in children and offer guidance for taking
the protective measures that will help to protect them, hence, to
reduce fractures.
Aim: Primary dysmenorrhea (PD) is among the most common gynecological diseases in young women presenting to emergency department. It has been shown that cytokines played roles in PD pathogenesis. ...Interleukin-4 (IL-4), a cytokine, regulates multiple biological functions. The objective of the present study was to examine possible relationship between IL-4 variable number of tandem repeat (VNTR) polymorphism and susceptibility to PD.
Methods: This study was based on a prospective cohort study design. A total of 120 patients with PD and 116 healthy controls, who presented to the emergency department between 01.12.2018 and 01.12.2019, were included in the study. IL-4 VNTR was genotyped by polymerase chain reaction (PCR). The results of the analyses were evaluated in terms of statistically significant differences.
Results: The prevalence of genotypes of P1/P1, P1/P2, and P2/P2 for IL-4 VNTR were 1.72%, 34.4%, and 63.7% in patients with PD, and 0.8%, 26.6%, and 72.5% in controls, respectively. There was no significant difference in distribution of genotypes and allele frequencies of IL-4 VNTR between the groups (p>0.05).
Conclusion: This research is the first study to examine the relationship between IL-4 VNTR and PD. The data of the present study did not support a relationship between IL-4 VNTR and PD risk.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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