Simultaneous shape and material optimization of sandwich panels with honeycomb core for additive manufacturing

This works deals with the problem of the optimum design of a sandwich plate composed of CFRP faces and Al honeycomb core. The proposed design strategy is a multi-scale numerical optimization procedure that does not make use of any simplifying assumption to find a global optimum configuration of the system. The goal of such a procedure consists in simultaneously optimizing the shape of the unit cell of the honeycomb core (meso-scale) and the geometrical as well as the material parameters of the CFRP laminated skins (meso and macro scales). To prove its effectiveness, the multi-scale optimization strategy is applied to the problem of the least-weight design of a sandwich panel subject to constraints of different nature: on the positive-definiteness of the stiffness tensor of the core, on the admissible material properties of the laminated faces, on the local buckling load of the unit cell of the core, on the global buckling load of the panel and geometrical as well as manufacturability constraints linked to the fabrication process of the honeycomb core

Simultaneous shape and material optimization of sandwich panels with honeycomb core for additive manufacturing

This works deals with the problem of the optimum design of a sandwich plate composed of CFRP faces and Al honeycomb core. The proposed design strategy is a multi-scale numerical optimization procedure that does not make use of any simplifying assumption to find a global optimum configuration of the system. The goal of such a procedure consists in simultaneously optimizing the shape of the unit cell of the honeycomb core (meso-scale) and the geometrical as well as the material parameters of the CFRP laminated skins (meso and macro scales). To prove its effectiveness, the multi-scale optimization strategy is applied to the problem of the least-weight design of a sandwich panel subject to constraints of different nature: on the positive-definiteness of the stiffness tensor of the core, on the admissible material properties of the laminated faces, on the local buckling load of the unit cell of the core, on the global buckling load of the panel and geometrical as well as manufacturability constraints linked to the fabrication process of the honeycomb core

Kidney and Sympathetic Nervous System in Hypertension

Współcześnie podkreśla się istotne znaczenie nadmiernej aktywności układu współczulnego w patogenezie nadciśnienia tętniczego oraz progresji przewlekłej niewydolności nerek. Zależności pomiędzy funkcją nerek a układem współczulnym są złożone. Z jednej strony, układ współczulny oddziałuje na funkcję nerek, np. wpływając na redystrybucję przepływu nerkowego, transport cewkowy sodu czy wydzielanie reniny i aktywację układu RAA. Z drugiej strony, nerki są prawdopodobnie źródłem bodźców dla chemo- i baroreceptorów układu naczynioruchowego/sympatycznego. Złożone mechanizmy regulacji ciśnienia tętniczego oraz ich wzajemne współzależności wywołują liczne zmiany czynnościowe oraz morfologiczne, związane z przebudową narządu ostatecznie, z zaburzeniami jego czynności. Znajomość powyższych elementów składowych prowadzi do pewnych wniosków terapeutycznych, pozwalających ustabilizować nadciśnienie tętnicze, zredukować jego wartości oraz zahamować progresję zmian morfologicznych i czynnościowych narządów.Nowdays in clinical investigations accented a very important influence of sympathetic overactivity in hypertension pathogenesis and progression of chronic renal failure.The correlation among renal function and sympathetic nerve system are difficult. On the one hand, the sympathetic nerve system affects renal function, i.e. renal hemodynamics flow, tubular sodium transport, renin secretion and activation of RAA system. On the other hand, the kidney is the source of activating afferent signals, presumably via stimulation of chemoreceptors and baroreceptors. The complicated mechanisms of blood pressure regulation and their correlation cause many functional and structural changes in organs and finally organs failure. Knowledge of these mechanisms give some therapeutic implications, help reduced blood pressure in hypertension patients and stopped development of functional and morphological changes in organs

A multi-scale approach for the simultaneous shape and material optimisation of sandwich panels with cellular core

This work deals with the problem of the optimum design of a sandwich panel made of carbon-epoxy skins and a metallic cellular core. The proposed design strategy is a multi-scale numerical optimisation procedure that does not make use of any simplifying hypothesis to obtain a true global optimum configuration of the system. To face the design of the sandwich structure at both meso and macro scales, a two-level optimisation strategy is employed: at the first level the goal is the determination of the optimum shape of the unit cell of the core (meso-scale) together with the material and geometric parameters of the laminated skins (macro-scale), while at the second level the objective is the design of the skins stacking sequence (skin meso-scale) meeting the geometrical and material parameters provided by the first-level problem. The two-level strategy is founded on the polar formalism for the description of the anisotropic behaviour of the laminates, on the NURBS basis functions for representing the shape of the unit cell and on the use of a genetic algorithm as optimisation tool to perform the solution search. To prove its effectiveness, the multi-scale strategy is applied to the least-weight design of a sandwich plate subject to constraints of different nature: on the positive-definiteness of the stiffness tensor of the core, on the admissible material properties of the laminated faces, on the local buckling load of the unit cell, on the global buckling load of the panel and geometrical as well as manufacturability constraints related to the fabrication process of the cellular core

Agricultural autumn drought and crop yield in 2011 in Poland

Over the recent years, drought has been occurring with an ever increasing frequency in Poland. The longer the rainless period lasts, the more acute its impacts are. Agricultural drought manifests itself as a prolonged period of water shortage for agricultural crops during their growth season resulting in yield reduction. Extent of drought was evaluated by the climatic water balance (CWB). Climatic water balance is an indicator that determines the state of humidification of the environment using data measured at meteorological stations. It is defined as the difference between atmospheric precipitation and evapotranspiration (in millimeters) calculated by an empirical formula taking into account: temperature, sunshine, and length of the day. CWB was calculated using meteorological data from 294 weather stations and weather posts across Poland. Spatial data from point measurements were interpolated using the Geographic Information System (GIS) software. Yield forecasts were made for major crops in Poland using agro-meteorological yield models and weather indices (WI). Yield figures were based on data from the Central Statistical Office of Poland (GUS). The autumn of 2011 was the driest in several dozen years in many localities of southeastern Poland. For instance, at the weather station in Puławy, the lowest level of precipitation had been recorded since 1871. Weather conditions prevailing in the growing season of 2012 were very beneficial for winter cereals and winter rapeseed. As for sugar beet, the weather also favored high yields over most of the growing season, except the final stage of growth. Notwithstanding the extreme drought in the autumn of 2011, the good weather conditions in the remaining part of the growth period caused the yields of winter crops and sugar beet to be high. The very scant autumn precipitation, even though it had negative impact on the germination of cereals, seedling emergence, and seedling growth, did not cause any major losses to yields. Water supplies from September precipitation combined with frequent morning mists, fogs, and dew mitigated the impact of prolonged drought and were sufficient to sustain the yields at an acceptable level

The evaluation of renin-angiotensin-aldosterone system blocking drugs use in hemodialysed patients

Wstęp Niewydolność serca jest częstą chorobą współistniejącą u chorych hemodializowanych. Leki blokujące układ RAA są standardowym leczeniem CHF, jednak brak badań oceniających skuteczność i bezpieczeństwo stosowania tych leków u chorych HD. Wielu autorów wskazuje na nieadekwatne leczenie chorób układu krążenia u chorych HD. Celem pracy była ocena częstości stosowania leków blokujących układ RAA oraz czynników ograniczających stosowanie tych leków u chorych HD. Materiał i metody Badanie jest przekrojową analizą 102 chorych HD w wieku 28&#8211;86 lat (średnia wieku 59 &#177; 13). W badaniu analizowano częstość stosowania leków blokujących RAA w zależności od występowania objawów CHF, ciśnienia tętniczego, stężenia potasu oraz adekwatności dializy. Wyniki Objawy niewydolności serca stwierdzono u 46 (45%) chorych HD. Lekami blokującymi układ RAA (ACEI lub ARB) leczonych było 46 (45%) chorych HD, w tym u 57% chorych z niewydolnością serca oraz 36% chorych bez objawów niewydolności serca (p < 0,05). Stężenie potasu było niższe u chorych z CHF leczonych lekami blokującymi układ RAA w porównaniu z pacjentami bez CHF leczonymi lekami blokującymi układ RAA (5,4 &#177; 0,6 vs. 6,0 &#177; 0,6 mmol/l; p < 0,01). Hiperkaliemia i hipotonia stanowiły główne przeciwwskazania do włączenia leków blokujących układ RAA. Wnioski W badaniu potwierdzono wysoką częstość występowania objawów niewydolności serca u chorych hemodializowanych. Stosowanie ACEI/ARB u chorych HD z objawami niewydolności serca wiąże się z mniejszym ryzykiem hiperkaliemii niż u chorych HD bez objawów niewydolności serca. Brak badań pozostawia bez odpowiedzi wiele pytań dotyczących optymalnego leczenia niewydolności serca u chorych hemodializowanych.słowa kluczowe: hemodializa, niewydolność serca, inhibitory konwertazy angiotensyny, potas, układ renina&#8211;angiotensyna&#8211;aldosteron Nadciśnienie Tętnicze 2007, tom 11, nr 4, strony 310&#8211;317.Background Congestive heart failure (CHF) is common concomitant disease in hemodialysed patients (HD). Renin-angiotensin-aldosterone system (RAA) blockers are standard therapy in CHF, but there is lack of studies evaluating the effectiveness and safety of such treatment in HD patients. Many authors point at inadequate cardiovascular therapy in hemodialysed patients. The aim of the study was to analyze the prevalence of RAA blocking drugs use in HD patients and factors limiting this therapy. Material and methods The study was cross-sectional analysis of 102 hemodialysed patients, aged 28-86 years (mean 59 &#177; 13). We investigated the prevalence of RAA blocking drugs use in respect to symptoms of CHF, blood pressure, potassium concentration and dialysis adequacy. Results Symptoms of CHF were found in 46 (45%) HD patients. RAA blocking drugs (angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blocker (ARB) were taken by 46 (45%) HD patients; in 57% patients with CHF and in 36% HD patients without symptoms of CHF, respectively (p < 0.05). Potassium concentration was lower in CHF patients treated with ACEI//ARB compared with patients without CHF treated with ACEI/ARB (5.4 &#177; 0.6 vs. 6.0 &#177; 0.6 mmol/l; p < 0.01). Hyperkalaemia and low arterial pressure were main contraindications for ACEI/ARB use in HD patients. Conclusions The study confirmed high prevalence of congestive heart failure symptoms in hemodialysed patients. ACEI/ARB use in HD patients with CHF is associated with lower risk of hyperkalaemia than in HD patients without CHF. Lack of clinical studies results in many questions regarding optimal therapy of CHF in HD patients unresolved. Arterial Hypertension 2007, vol. 11, no 4, pages 310-317

Medieval multilingualism in Poland:Creating a corpus of Greater Poland court oaths (ROThA)

In this paper we introduce the research plan for the preparation of a searchable electronic repository of the earliest extant legal oaths from medieval Poland drawing on the expertise in historical corpus-building developed for the history of English. The oaths survive in the overwhelmingly Latin land books from the period between 1386 and 1446 for six localities Greater Poland, in which the land courts operated: Poznań, Kościan, Pyzdry, Gniezno, Konin and Kalisz. A diplomatic edition of the oaths was published in five volumes by Polish historical linguists (Kowalewicz & Kuraszkiewicz 1959–1966). The edition is the only comprehensive resource of considerable scope (over 6300 oaths from the years 1386–1446) for the study of the earliest attestations of the Polish language beyond glosses. Recognising some limitations, but most of all its unparalleled coverage of the coexistence of Latin and the vernacular, the ROThA project embarks on transforming the edition into an open up-to-date digital resource. We thus aim to facilitate research into the history of Polish and Latin as well as of the legal system and the related social and linguistic issues of the period

From Saussure to sociology and back to linguistics

The article highlights a semiotically relevant aspect of Niklas Luhmann’s Theory of Social Systems: its reception of the Saussurean dichotomies signifiant/signifié and langue/parole. Luhmann’s position is weighted against the Cours as well as Saussure’s original writings, sampling their approaches to form, meaning, the sign’s two-sidedness, and the relation of linguistic structure and speech events. Ultimately, the article proposes a social ontology of linguistic abstraction in line with general semiology that explains the motility of language through communication, thereby accounting for variability and optionality. It also indicates as to how the theoretical framework can feed into a model of linguistic description.Peer Reviewe