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1

Workpiece temperature variations during flat peripheral grinding

Smirnov V. A., Repko A. V.

Management Systems in Production Engineering

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2018

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nr 2 (26)

93--98

EN

The paper presents the results of researches of temperature variations during flat peripheral grinding. It is shown that the temperature variations of the workpiece can reach 25...30% of the average values, which can lead to some thermal defects. A nonlinear two-dimensional thermophysical grinding model is suggested. It takes into account local changes in the cutting conditions: the fluctuation of the cut layer and the cutting force, the thermal impact of the cutting grains, and the presence of surface cavities in the intermittent wheel. For the numerical solution of the problem, the method of finite differences is adapted. Researches of the method stability and convergence are made, taking into account the specific nature of the problem. A high accuracy of the approximation of the boundary conditions and the nonlinear heat equation is provided. An experimental verification of the proposed thermophysical model was carried out with the use of installation for simultaneous measurement of the grinding force and temperature. It is shown that the discrepancy between the theoretical and experimental values of the grinding temperature does not exceed 5%. The proposed ther-mophysical model makes it possible to predict with high accuracy the temperature variations during grinding by the wheel periphery.

2

Analiza oparzeń ciała oraz dojścia do zgonu mężczyzny na podstawie podjętych w sprawie ustaleń i zdjęć

Włodarczyk R.

Bezpieczeństwo i Technika Pożarnicza

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2011

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Nr 4

127-134

PL

Artykuł traktuje o problematyce związanej z wykorzystaniem ognia do dokonania czynów przestępnych i ich maskowania, ustaleniem przyczyn wystąpienia poparzeń na ciele zwłok ludzkich, rodzaju śmierci gwałtownej, tożsamości ofiary i potencjalnego sprawcy tego czynu. Wszelkie działania w trakcie zabezpieczenia terenu, oględzin miejsca zdarzenia, z obecnymi tam zwłokami, powinny być tak ukierunkowane, żeby później jak najbardziej efektywnie można było wykorzystać ujawnione i pobrane dowody, stworzyć wersję kryminalistyczną i wyjaśnić wszystkie okoliczności danej sprawy. Problemy z fachowością i rzetelnością ekip pracujących na poszczególnych etapach postępowania związanego z pożarem (nie tylko zresztą) ciągle się przewijają w doniesieniach literaturowych, opisujących przypadki z praktyki kryminalistycznej. Nieustannie są więc aktualne, bo z jednej strony - nie do wszystkich dociera fakt konieczności solidnego przeprowadzenia czynności oględzinowych na miejscu zdarzenia, z drugiej zaś strony - brak przepływu informacji na dalszych etapach poznawczych sprawia, że skutkuje to negatywnie na przebieg całego procesu. Na przykład często biegli z zakresu medycy sądowej, mający przeprowadzić sekcję, nie mają żadnych informacji na temat sposobu ujawnienia i zmian stwierdzanych na ciele zwłok, podczas oględzin miejsca zdarzenia. Autopsja najczęściej prowadzona jest kilka dni po śmierci osoby, dlatego skutkuje to w ten sposób, że część istotnych informacji (w tym wypadku o zmianach termicznych z pęcherzami oparzelinowymi, przy pojawianiu się pęcherzy gnilnych - pochodzących od bakterii z otoczenia denata) nie jest przez nich w ogóle "odczytywana". Dotyczy to również biegłych z innych dziedzin, którzy nie mając przekazanej wiedzy na temat specyfiki powstania i cech charakterystycznych pożaru, lokalizacji i rozmieszczenia względem siebie śladów i/lub dowodów rzeczowych, oddziaływania czynników środowiskowych etc., nie są w stanie wyjaśnić pewnych okoliczności, a tym bardziej odnieść się do motywu, jakim kierował się sprawca (-cy). Do podjętej problematyki z pożarnictwa dołączono kazus, wydaną na ten temat opinię biegłego, dwa zdjęcia i ich analizę. Ma to na celu "zasianie wątpliwości" co do sprawcy czynu. Przyjęto bowiem, że był nim sam denat. Rzeczywiście, na ujawnionych zwłokach występują rozległe ślady oparzeń, ale jednoznacznie nie ma podstaw twierdzić, że mamy do czynienia z samobójstwem, a nie z zabójstwem. Przyczyną zaistniałego stanu rzeczy było nie tylko działanie wysokich temperatur na ciało ofiary, z różnym stopniem nasilenia, ale również czas, jaki upłynął od momentu zdarzenia do ujawnienia zwłok, warunki atmosferyczne i środowiskowe panujące w terenie oraz brak dostatecznej wiedzy na temat sposobu prowadzenia procesu wykrywczego i zgromadzonego w sprawie materiału.

EN

This paper discusses the issues related to the use of fire in committing criminal acts and their masking, finding the causes of burns on the body of human corpse, the type of violent death, the identity of the potential victim and the potential perpetrator. Any and all actions while sealing off the scene, inspecting it, including the human corpse as found there should be so targeted that, thereafter, disclosed and collected traces could be used as effectively as possible, to create a forensic concept and to explain all circumstances of the case in question. In the fire-related issues a casus, an expert's advice, two pictures and their analysis were incorporated. The aim was to "arouse doubt" as regarded the perpetrator. For it was assumed, that he was the deceased himself. Indeed, on the corpse found, extensive traces of burns were discovered, but clearly there was no basis whatsoever to say that we were dealing with suicide, not murder. The reason of the given status quo was not only the effects of high temperatures on the victim's body, with varying degrees of severity, but also the time elapsed between the incident and the discovery of the corpse, weather and environmental conditions which prevailed in the area and the lack of sufficient knowledge on both the discovering process and the evidence collected in the matter.

3

Zmienność temperatury gruntu w Hornsundzie w okresie 1979-1999

Miętus M., Filipiak J.

Przegląd Geofizyczny

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2001

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Z. 4

323-337

EN

In the paper the analysis of the variability of the soil temperature on the Polish polar station in Hornsund, situated in southwestern part of Spitsbergen, has been presented. The soil temperature data from the depths 5, 10, 20, 50 and 100 cm cover the period 1979-1999. In the annual cycle of the soil temperature variability the 8-month period, while the soil is frozen, can be observed. Positive values of temperature in the whole-analyzed profile occur only during the 3-month-lasting period from July to September. In the cool season the highest temperatures are recorded in the deeper layer, additionally the greatest values of the standard deviation in the considered depths are met. In the warm season the temperature decreases with the depth. During the spring and autumn, when the isothermal conditions in the soil profile are observed, the reversion of the temperature profile is recorded. The most thermally active layer is the upper one - deep to 20 cm. Reaction of deeper layers to the thermal processes above the ground and in the upper layers is weaker and time-delayed. The greatest differences of temperature between the lowest layer and the upper ones are recorded during the polar night. Air temperature significantly influences the variability of the soil temperature. The relationships between the soil temperature and the other meteorological elements i.e. sunshine duration, cloudiness, persistence of snow cover and its depth are not confirmed by the high values of correlation coefficients. The annual variability of the soil temperature can be approximated with the first harmonic. Below the depth of 184 cm maximum soil temperature do not exceed 0°C. In the whole examined profile the positive long-term tendencies of the temperature are observed, but the statistically significant trend (+0.126°C/year) occurs only on depth 10 cm.

4

Rekonstrukcja zmian temperatury powierzchni gruntu w Polsce w ostatnim 500-leciu na podstawie profili geotermicznych

Majorowicz J., Šafanda J., Przybylak R., Wójcik G.

Przegląd Geofizyczny

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2001

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Z. 4

305-321

EN

Reconstruction of the ground surface temperature history in Poland was derived from the in-version of the temperature profiles with depth in over 20 wells. Temperature histories for the period 1500 A.D. till 1977 A.D. agree well with instrumental record of the surface air temperature available for the last two centuries. We are observing large warming since early 19th century of the magnitude of 0.6-0.9°C preceded by a colder climate since 1500 A.D. interrupted by a warmer one with a local maximum in the 1700 A.D. The climatic reconstructions based on the deepest wells (> 470 m depth) show very god correlation among groups of wells. The statistical correlation of the reconstructed histories (from the well temperature data) with the instrumental record (air temperature) from the homogeneous Warsaw series is very high. Statistical correlation coefficient as high as 0.9 is seen for some groups of wells. Geothermal data and their inversion is the only direct physical method to determine the value of warming/cooling events in the past. This is done without the need of calibration based on the correlation with the present air surface temperature record as needed for the proxy reconstructions (tree rings etc

5

O dynamice lagun liberyjskich w czasie pory suchej

Strupczewski W.G., Osuch M.

Przegląd Geofizyczny

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2001

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Z. 4

339-349

EN

Paper reports findings on hydrological regime of Liberian lagoons during dry season collected during over two years staying in Liberia. While traveling along shoreline in Liberia one has to cross several rivers' mouths, which are very shallow during a dry season. Hydro-meteorological processes and sea activity control process of closing and opening of rivers mouths. Although the closure of the mouth of big rivers has never been recorded, such tendency is observed at the end of dry season. In his way along seashore, one is passing by a countless number of coastal lagoons with their own drainage area. The lagoons are in the various stage of development in respect to sea-lagoon communication: Two-way communication. It is a rule during rainy season. Downstream communication only. Sea is open for lagoon, while lagoon is closed for the sea in the advanced stage of the construction of sand bar, excluding short period of high tides. Upstream communication only. The sand bar is so high that it prevents lagoon from reaching the sea. No water exchange between sea and lagoon. Liberian lagoons show unusual phenomenon of thermal inversion. There are several pits in lagoon where the temperature of the bottom layer is 3-6°C warmer tan the surface layer. The behavior of the Po river during dry season is described. The river of such size spans a gap between big Liberian rivers discharging into the sea and coastal lagoons with small catchment and in particular between fluvial and stemmed lagoons. The presented description of lagoon dynamics in respect to storage of mass, energy as well as thermal and salinity stratification shows that there are still some new challenging scientific problems, which calls for multidisciplinary investigation.

6

Wpływ warunków cyrkulacyjnych na zmienność temperatury wody u południowych wybrzeży Zatoki Pomorskiej

Kowalewska-Kalkowska H.

Zeszyty Naukowe. Marine Sciences / Uniwersytet Szczeciński

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2000

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Nr 6

19-38

EN

The work presents the results of studies on the influence of circulation conditions on variability of water temperature at the southern toast of the Pomeranian Bay. In order to resolve the problem mean daily water temperature values as measured at Międzyzdroje and Gozdowice as well as mean air temperature values at Świnoujście were analysed under different circulation conditions to obtain statistical relations between them. Simple and multiple regression analyses were performed. The period 1971-1980 u taken into the examination. In the ten year period 1971-1980 the air circulation coming from the east sector was prevailing from February to July and coming from the west sector was prevailing from August to January. For these two periods the highly statistically significant coefficients of correlation between water temperature as measured at Międzyzdroje a Gozdowice as well as air temperature at Świnoujście made possible to describe inshore water temperature using the equations of simple and multiple regression. As the highly statistically significant coefficients of correlation were also obtained for the periods different types of air circulation so for all these periods the equations of simple a multiple regression were also written. The multiple regression equations show that the influence of water temperature the Odra River on inshore water temperature was stronger than the influence of air temperature, especially during the periods of air circulation coming from south-west north-west directions. The effect of air temperature was the strongest when the circulation from north-east was recorded. In that case the influence of water temperature of the Odra was decreased.

7

Wieloletnia zmienność temperatury powietrza w Szczecinie (1836-1995)

Wiśniewski B., Medyna P., Wolski T.

Zeszyty Naukowe. Marine Sciences / Uniwersytet Szczeciński

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2000

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Nr 6

7-18

EN

The presumption of this publication is description of the air temperature in Szczecin in the period 1836-1995. On the basis of 160-year series, the change of climatic epoch in 19th and 20th century was described and perennial cycles in air temperature were defined. For this purpose, various statistical methods were used. Analysis indicates, that seasonally and yearly changes of air temperature in research periods in Szczecin are quite strong variable: -The perennial variability in air temperature of cold seasons is considerably bigger than warm seasons. -On the whole length of 160-year series there is lack of extremely warm periods. The most frequently occurring are the moderate years and seasons. -The quasi 7-year cycle of air temperature was confirmed.

8

Współczesne trendy zmian temperatury powietrza w Polsce

Smukała P.

Zeszyty Naukowe. Marine Sciences / Uniwersytet Szczeciński

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1999

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Nr 5

73-93

EN

Statistical methods used in the work have confirmed the results of study on the observed climate of Poland. According to the analysis which was carried on the topic distinguishing fluctuations of temperature changes in July and winter occurred. At the end of 80 ties winter warning because of its resistance take the features of an important climate anomaly. The cumulative deviations described by O.A Drozdov and A.S. Grigorieva have proved the existence of significant tendency in winter months. The growing tendency of the last decade is characteristic for the whole winter season. Hot summers of the last decade have disturbed the tendency of falling temperatures of the summer in Poland. The significant tendency of fluctuating air temperatures which were observed on the basis of cumulative deviations in June end July only. There haven't been observed any significant temperature fluctuations in other summer months as well as in the whole summer season.