A statistical evaluation of six classes of hydrocarbons: which classes are promising for future biodegraded ignitable liquid research?

The current methods for identifying ignitable liquid residues in fire debris are heavily based on the holistic, qualitative interpretation of chromatographic patterns with the mass spectral identification of selected peaks. The identification of neat, unweathered ignitable liquids according to ASTM 1618 using these methods is relatively straightforward for the trained analyst. The challenges in fire debris analysis arise with phenomena such as evaporation, substrate interference, and biodegradation. These phenomena result in alterations of chromatographic patterns which can lead to misclassifications or false negatives. The biodegradation of ignitable liquids is generally known to be more complex than evaporation [20], and proceeds in a manner that is dependent on numerous factors such as: composition of the petroleum product/ignitable liquid, structure of the hydrocarbon compound, soil type, bacterial community, the type of microbial metabolism that is occurring, and the environmental conditions surrounding in the sample. While nothing can be done to prevent the biodegradation, continued research on biodegraded ignitable liquids and the characterization of the trends observed may be able to provide insight into how an analyst can identify a biodegraded ignitable liquid residue. This research utilized normalized abundance values of select ions from pre-existing gas chromatography-mass spectrometry (GC-MS) data on samples from three different gasoline and diesel biodegradation studies. A total of 18 ions were selected to indicate the presence of six hydrocarbon classes (three each for alkanes, aromatics, cycloalkanes, naphthalenes, indanes, and adamantanes) based on them being either base peaks or high abundance peaks within the electron impact mass spectra of compounds within that hydrocarbon class. The loss of ion abundance over the degradation periods was assessed by creating scatter plots and performing simple linear regression analyses. Coefficient of determination values, the standard error of the estimate, the slope, and the slope error of the best fit line were assessed to draw conclusions regarding which classes exhibited desirable characteristics, relative to the other classes, such as a linear degradation, low variation in abundance within the sampling days, and a slow rate of abundance loss over the degradation period. Additional analyses included two-way analysis of the variance (ANOVA), to assess the effects of time as well as different soil type on the degradation of the hydrocarbons, stepwise multinomial logistic regressions to identify which classes were the best predictors of the type of ignitable liquid, and one-way ANOVAs to determine where the differences in the ratios of hydrocarbon classes existed within each of the ignitable liquids, as well as between the two liquids. Hydrocarbon classes identified as exhibiting characteristics such as slow and/or reliable rates of abundance loss during biodegradation are thought of as desirable for future validation studies, where specific ranges of hydrocarbon class abundance(s) may be used to identify the presence of a biodegraded ignitable liquid. Classes of hydrocarbons that have experienced biodegradation that maintain an abundance close to that of a neat, non degraded counterpart, or that reliably degrade and have predictable abundance levels given a particular period of degradation, would be instrumental in determining whether or not an unknown sample contains an ignitable liquid residue. It is the hope that these assessments will not only provide helpful information to future researchers in the field of fire debris analysis, but that they will create interest in the quantitative, statistical assessment of ignitable liquid data for detection and identification purposes

What student and school factors increase disadvantages in special needs students? An investigation of Student Learning Growth in Students with IEPs

This study used public-use data from the National Center for Education Statistics’s (NCES) Early Childhood Longitudinal Program, Kindergarten Class of 2011 (ECLS-K: 2011) to examine math and reading learning growth from 4th to 5th grade among student with and without Individualized Education Programs (IEPs). When comparing the non-IEP student sample to the IEP student sample, a disproportionate number of minority students and students of low socioeconomic status were observed in the IEP student group. Among non-IEP students, significantly decreased score growth was predicted in students who were Black, Hispanic, had less highly educated parents, were from a low income household, or attended a school with a high percentage of students eligible for free or reduced price lunches (FRPLs). Among IEP students, the only significant predictors of decreased score growth were being Black and attending a school with a high percentage of students eligible for FRPLs. Potential reasoning for few significant findings among IEP students may be the broadness of the IEP status variable, suggesting future researchers may learn more about student, parent, teacher, and school factors negatively impacting students in special education by more narrowly defining IEP students by type of disabilities, services used, or IEP goals which were unattainable in the public use data file for the ECLS-K

pulsed electric field assisted juice extraction of frozen thawed blueberries

Pulsed electric field is an efficient method for cell membrane permeabilization of food tissues with most research being done on fresh plant cells. Freeze/thawing is also known to be capable of cell membrane permeabilization. In this work, frozen/thawed European blueberry (Vaccinium myrtillus L.) fruits were treated with pulsed electric field in order to further enhance the cell membrane permeabilization and, hence, the quality of blueberry juice during the subsequent pressing process. Blueberries tissues were exposed to 20 μs monopolar square wave pulses of different electric field strength (E = 1–3–5 kV cm-1) and total specific energy input (WT = 1–5–10 kJ kg -1), with their permeabilization being characterized by electrical impedance measurements and cell disintegration index (Zp). The juice, obtained after pressing (1.32 bar), was characterized for total polyphenols, anthocyanins content and antioxidant activity. The cell disintegration index (Zp) significantly (p < 0.05) increased from 0.2 up to 0.6 with increasing pulsed electric field treatment intensity (E and WT). As a results, in comparison with control, pulsed electric field treatment induced a slightly higher release of polyphenols (up to +8.0%) and anthocyanins (up to +8.3%), thus improving the antioxidant activity of the juice (up to +16.7%). In conclusion, frozen/thawed blueberries could be pulsed electric field treated in order to further increase juice quality

Optimization of Ultrasound-Assisted Extraction of Anthocyanins from Mulberry, Using Response Surface Methodology

Mulberry is one of the most widely used traditional Chinese medicines. Anthocyanins are the main bioactive components of mulberry, and possess important biological activities, such as antimicrobial, anti-inflammatory and antioxidant activities. This study investigated the ultrasound-assisted extraction (UAE) of anthocyanins from mulberry by using response surface methodology (RSM). The extraction conditions associated with anthocyanin yield, including extraction solvent, liquid-to-solid rate, temperature and extraction time, are discussed. The optimal conditions obtained by RSM for UAE from mulberry include 63.8% methanol contains 1% (v/v) trifluoroacetic acid (TFA), 43.2 °C temperature, 23.8 (v/w) liquid-to-solid ratio, and 40 min time for the maximum yield (64.70 ± 0.45 mg/g). The results indicated that the UAE can be an effective method for the extraction of some active components from plant materials

Research of small wind power plant

Šio darbo tikslas – analitiniais ir eksperimentiniais tyrimais nustatyti mažos galios horizontaliosios ašies vėjo jėgainės ir jos vėjaračio charakteristikas. Naudojantis atliktų tyrimų rezultatais, kuriuose buvo tirta ir nustatyta vėjaračio charakteristikos bei pačių vėjo jėgainių efektyvumas galima teigti, kad naudojant programinę įrangą nustačius suprojektuotos vėjo jėgainės vėjaračio aerodinamines savybes tikslinga patikslinti eksperimentiniais tyrimais. Darbe nustatyta, kad didelę įtaką jėgainės darbo efektyvumui turi vėjaračio aerodinaminės savybės. Šias savybes lemia vėjarčio menties forma bei aerodinaminis profilis. Išanalizuota eksperimentiniu būdų atliktų tyrimų gauti rezultatai tarp teorinio modelio ir realiai veikiančios vėjo jėgainės. Nustatyta, kad tarp teorinio modelio ir realiai veikiančios vėjo jėgaines rezultatų nesutapimas siekia – 15 %.The Paper objective is to establish the characteristics of a low-power horizontal axis wind turbine and its wind wheel by analytical and experimental researches. According to the results of the researches, carried out for the purpose of research and establishment of the wind wheel characteristics and efficiency of wind turbines, it can be stated it is reasonable to specify aerodynamic properties of the wind wheel of the wind turbine, designed using software, by experimental researches. It was established in the Paper that aerodynamic properties of the wind wheel have great impact on the wind turbine operation efficiency. These properties are predetermined by the wind wheel vane shape and aerofoil profile. The results of experimental researches of theoretical model and real wind turbine were analysed. It was established that non-conformity between the results of research of theoretical model and real wind turbine reaches 15%.Žemės ūkio akademijaVytauto Didžiojo universiteta

Analysis of anthocyanin content in bilberry (Vaccinium myrtillus L.) fruit crude drugs by high-performance liquid chromatography method

Bilberry (Vaccinium myrtillus L.) is rich in flavonoids (major part anthocyanins), tannins, phenolic and organic acids, and other biologically active compounds. Anthocianins possess a broad spectrum of therapeutic properties. Variation in anthocyanin content of bilberry fruit crude drugs is significant in optimizing collection conditions. Bilberry (Vaccinium myrtillus L.) crude drug samples were collected in July–September of 2006 in natural environment in the territory of Lithuania. Ultrasonic extraction was applied using methanol as solvent. Acidic hydrolysis was performed. Qualitative and quantitative composition of five major anthocyanidins (delphinidin, cyanidin, petunidin, peonidin, and malvidin) was estimated by high-performance liquid chromatography in frozen fruits. Cyanidin predominated in all crude drug samples. Dynamics of variation in qualitative and quantitative composition of anthocyanidins was estimated in bilberry fruits collected during vegetation period. The greatest total amount of all analyzed anthocyanidins was determined at the end of investigated period. Variation in qualitative and quantitative content of anthocyanidins in bilberry fruits collected in different regions of Lithuania was estimated as well. The greatest total amounts of anthocyanidins were found in samples collected in Krikštoniai forest (1.78%) and Prienai pinewood (2.13%) and the lowest amounts – in samples collected in Balkasodis forest (1.14%) and Ryliškės forest (0.99%). Significant variation in anthocyanidin content reaching 28.40% (delphinidin) was determined in bilberry fruits. It is important for the standardization of bilberry fruit crude drugs

Locomotion, physiological demands and sport contest model playing on different surface court in youth tennis players (15–17 years age)

Problem. There are no training and performance models of youth tennis players. Due to this problem training models of highly skilled tennis players are mainly applied. Such practical experience is questionable, because the effect for the pattern of the game, character of the locomotion and physiological demands are not defined by evaluating features of age, skill, functional abilities of athletes and especially playing on different surface courts. Hypothesis. Playing on the clay courts leads to performance of higher locomotion, physiological demands and sport contest model in specialized training stage of young tennis players (15–17 years age). The aim. To establish the indicators of locomotion, physiological demands and sport contest model playing on different surface courts in specialized training stage young tennis players (15–17 years age). Objectives: 1. Identify demands of locomotion playing on different surface courts in specialized training stage young tennis players (15–17 years age). 2. Identify indicators of sport contest playing on different surface courts in specialized training stage young tennis players (15–17 years age). 3. Identify physiological demands playing on different surface courts in specialized training stage young tennis players (15–17 years age). Material & Methods. Four young tennis players aged 15–17 were participating in the research (age – 16,25 ± 0,5 years, height – 182,5 ± 8,23 cm, body mass – 67,24 ± 3,30 kg, mastership – 12,75 ± 3,86 national ranking, training experience – 10,75 ± 0,5 years). Aerobic fitness (Cooper test) was performed for the young tennis players and six matches of one set were played. The protocol of sport contest and device (Polar RS300X, Finland), that measured the locomotion and physiological indicators, was used. Conclusions. Young tennis players covers 1000 meters per set on the carpet court, exceeded nearly 30 percent more on the clay court (1280). Court surface does not affect the average velocity (~ 1,5 km.h–1) and duration of the game (51–55 minutes) for the 15–17 years old tennis players. Young tennis players reach 7,8 km.h–1 maximum speed but lower average speed of set (1,4 km.h–1 ) playing on the clay court, than on the carpet court (respectively 6,5 km.h–1 and 1,7 km.h–1). Physiological indicators of young tennis players are adequate for elite tennis players. Fidings suggests to assume that young tennis players may to compete with elite tennis players. Young tennis players perform more actions on the clay court. The winner of the set is determined by mastership of tennis player as compared with skill to play on the selected surface. Keywords: sport contest model in tennis, fitness & performance