Primjena umjetnih neuronskih mreža za predviđanje optimalnih parametara sušenja furnira za proizvodnju furnirske ploče visokih mehaničkih svojstava

Veneer drying is the manufacturing process in the plywood industry that most affects energy consumption and panel properties such as bonding and bending. Therefore, the veneer drying temperature and moisture content should be accurately adjusted. Moreover, the determination of veneer thermal conductivity is as important as these two parameters and the thermal conductivity values should also be specifi ed when forming the drying programs. This study aimed to predict the optimum values of the veneer drying temperatures, moisture content and thermal conductivity, which gave the best mechanical properties, by artifi cial neural network (ANN) analysis. Poplar (Populus deltoidesI-77/51) and spruce (Picea orientalis L.) veneers and urea formaldehyde (UF) resin were used in the production of plywood. The thermal conductivity of veneer and the bonding, bending strength and elasticity modulus of the panels were tested by the relevant standards. The most accurate and reliable prediction models were obtained by analyzing the experimental data with ANN. The optimum veneer drying temperature, moisture content and thermal conductivity values that gave the best values for all three mechanical properties were 149 °C, 6.2 % and 0.02668 W/mK for poplar and 116 °C, 4.4 % and 0.02534 W/mK for spruce.Sušenje furnira proizvodni je proces u industriji furnirskih ploča koji najviše utječe na potrošnju energije i svojstva ploče kao što su čvrstoća lijepljenja i savijanja. Stoga je potrebno točno prilagoditi temperaturu sušenja i sadržaj vode u furniru. Nadalje, određivanje toplinske vodljivosti furnira jednako je važno kao temperatura sušenja i sadržaj vode, pa je pri izradi programa sušenja potrebno specificirati i vrijednosti toplinske vodljivosti. Cilj ovog istraživanja bio je primjenom umjetne neuronske mreže (ANN) predvidjeti vrijednosti optimalne temperature sušenja, sadržaja vode i toplinske vodljivosti furnira koje će rezultirati najboljim mehaničkim svojstvima ploče. Za potrebe ispitivanja furnirske su ploče proizvedene od furnira topolovine (Populus deltoidesI-77/51) i furnira smrekovine (Picea orientalis L.) te su slijepljeni urea formaldehidnom smolom (UF). Prema odgovarajućim standardima ispitani su toplinska vodljivost i čvrstoća lijepljenja furnira te čvrstoća na savijanje i modul elastičnosti ploča. Najtočniji i najpouzdaniji modeli predviđanja dobiveni su analizom eksperimentalnih podataka uz pomoć umjetne neuronske mreže. Optimalne vrijednosti temperature sušenja, sadržaja vode i toplinske vodljivosti uz koje se postižu najbolja mehanička svojstva za furnirske ploče od topolovine iznosile su 149 °C, 6,2 % i 0,02668 W/mK, a za furnirske ploče od smrekovine 116 °C, 4,4 % i 0,02534 W/mK

Predviđanje optimalne gustoće ekspandiranog polistirena za najbolje performanse toplinske izolacije polistirenske kompozitne iverice primjenom umjetne neuronske mreže

The objective of this study is to predict the optimum expanded polystyrene (EPS) densities for the best insulation properties of the particleboards manufactured with waste EPS instead of formaldehyde-based adhesives used in particleboard production with artificial neural network (ANN). For this purpose, the waste EPS particles of five different densities were used in the production of composite particleboards. The experimental dana used in the study were obtained from the previous study. Half of the beech, poplar, alder, pine and spruce chips were dried in a drying oven and the other half were naturally conditioned at room temperature, and then 18 mm thick three-layer composite particleboards were produced. The thermal conductivity of panels was determined according to ASTM C 518. The prediction model with the best performance and acceptable deviations was determined by using statistical and graphical comparisons between the experimental data and the prediction values obtained as a result of ANN analysis. Then, using this prediction model, the thermal conductivity coefficient values were estimated for the intermediate EPS densities that were not experimentally tested. According to the analysis findings, the thermal insulation performance for both beech and spruce polystyrene composite particleboards (PCP) panels increased with using of waste EPS foams with a density of 30 kg/m3. The lowest thermal conductivity values were obtained from the EPS waste foams with the density of 18, 13 and 22 kg/m3 for the PCP panels produced with poplar, alder and pine in the natural drying, respectively. In the technical drying, these values were found to be 15, 14 and 11-13 kg/m3, respectively. Technical drying showed much better thermal performance than natural drying while poplar indicated the best performance among the wood species.Cilj je ove studije primjenom umjetne neuronske mreže (ANN) predvidjeti optimalne gustoće ekspandiranog polistirena (EPS) radi postizanja najboljih izolacijskih svojstava iverice proizvedene s otpadnim EPS-om umjesto s ljepilom na bazi formaldehida, kakvo se rabi u proizvodnji iverice. Stoga je za proizvodnju iverice upotrijebljen otpadni EPS pet različitih gustoća. Eksperimentalni podatci primijenjeni u studiji dobiveni su prijašnjim istraživanjem. Jedna je polovica iverja bukovine, topolovine, johovine, borovine i smrekovine osušena u sušioniku, a druga je polovica iverja kondicionirana na sobnoj temperaturi. Od osušenoga i kondicioniranog iverja proizvedene su troslojne kompozitne iverice debljine 18 mm. Toplinska vodljivost ploča određena je metodom ASTM C 518. Predikcijski model najboljih svojstava i prihvatljivih devijacija određen je statističkom i grafičkom usporedbom eksperimentalnih podataka s vrijednostima predviđenima ANN analizom. Potom su primjenom predikcijskog modela procijenjeni koeficijenti toplinske vodljivosti za one gustoće ekspandiranog polistirena koje nisu eksperimentalno ispitane. Prema toj analizi, termoizolacijska svojstva polistirenske kompozitne iverice (PCP) od bukovine i smrekovine poboljšana su pjenom od otpadnog EPS-a gustoće 30 kg/m3. Najniže vrijednosti toplinske vodljivosti za polistirensku kompozitnu ivericu od prirodno osušene topolovine, johovine i borovine dobivene su uz uporabu pjene otpadnog ESP-a gustoće 18, 13 i 22 kg/m3. Za polistirensku kompozitnu ivericu od tehnički osušenog iverja te su vrijednosti bile 15, 14 i 11-13 kg/m3. Tehničkim sušenjem iverja postignuta su znatno bolja toplinska svojstva polistirenske kompozitne iverice nego prirodnim sušenjem, a topolovina je pokazala najbolja svojstva od svih ispitivanih vrsta drva

From Human Trafficking to Human Resources: Acquisition of Victims of Human Exploitation in Terms of Human Resources

Human exploitation is one of the most noncompliant and unacceptable invasion of human rights. Even though generally developed countries are interested in the effects on their own political and economical scheme, actually socio-psychological conditions of victims should be considered regarding the human exploitation. These people who are forced to be in a totally different environment are having a difficulty of integration. Integration and rehabilitation will be effective if applied in all areas with many extensions. In this paper, human exploitation in working places and human resources policies and strategies which would make the integration period shorter for refugee employees

Investigation of cesarean sections at Konya Training and Research Hospital Obstetrics and Gynecology Department between 2010 and 2015

Objective: Analysis of the annual distribution of cesarean sections and indications between 2010 and 2015 in our clinic. Material and methods: Medical records of 10,437 cesarean section patients from a total number of 24,283 deliveries performed at Department of Obstetrics and Gynecology between 2010–2015 were evaluated retrospectively. The indications for Cesarean section were analyzed and compared based on years. Results: The lowest cesarean section rate was 18.67% in 2011 and the highest rate was 24.5% in 2013, and the annual rates were close to each other in this 6-year period (p > 0.05). History of uterine surgery was the indication with the highest rate of 49.52%, while fetal distress was the second most frequent with 12.53%; presentation anomalies were observed as the most frequent third indication with 7.55%, and umbilical cord prolapse was the least frequent indication with 0.33%. Conclusions: Patient education about normal delivery and providing means for pain control during normal delivery, improvement in physical conditions of the clinics, frequent and regular training of the assisting staff with obstetrics physicians are important to diminish the rates of primary cesarean sections. In addition, a normal delivery after a previous cesarean section must be encouraged

Comparison of thermal performances of plywood shear walls produced with different thermal insulation materials

Shear walls are one of the envelopes of light-frame wooden buildings where thermal insulation is most required. The thermal performance of shear walls can vary according to the type, properties and thickness of the wood and insulation materials used in their production. In this study, it was aimed to compare the thermal performances of plywood shear walls produced with different thermal insulation materials. For this aim, the archetype walls with properties similar to commonly used plywood shear walls were designed and produced for each thermal insulation material type and wood specie. The shear wall groups were formed by using Scots pine (Pinus sylvestris), black pine (Pinus nigra) and spruce (Picea orientalis) as wood species and cellulose, flax, felt, XPS, EPS, sheep’s, rock and glass wool as thermal insulation materials. Thermal conductivity of the shear wall groups was determined according to the ASTM C518-04 standard. Thermal resistance and other thermal performance parameters were calculated using the thermal conductivity values. As a result of the study, rock wool was the best thermal insulation material among the Scots pine shear wall groups while glass wool was the best thermal insulation material among the black pine and spruce shear wall groups. The shear walls produced with EPS foam boards indicated the worst thermal performance among all group

Successful Conservative Management of a Dislocated IUD

Background. Intrauterine contraceptive devices (IUDs) are widely utilized all over the world owing to their low cost and high efficacy. Uterine perforation is a rare complication that may occur at IUD insertion resulting in extrauterine location of the IUD. Traditionally, surgical removal of dislocated IUDs has been recommended. Case. A 68-year-old patient who had an IUD (Lippes loop) inserted 32 years ago and whose routine examination incidentally revealed a dislocated IUD in the abdominal cavity. The patient remained asymptomatic during three years of follow-up and the IUD was left in place. Conclusion. Asymptomatic patients, whose vaginal examinations and ultrasonography or X-ray results reveal a dislocated IUD, may benefit from conservative management