bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zur Reaktionstechnik von Blasensäulen‐Reaktoren mit suspendiertem Katalysator
Authors: Kölbel H. , Matsuura T. , Hammer H. 
Published: December 2004

AbstractZur Darstellung der Wechselwirkung zwischen einer heterogen‐katalytischen Reaktion, dem Stoffübergang von der Gasphase in die Flüssigkeitsphase und den hydrodynamischen Eigenschaften eines Gas/Flüssigkeits‐Reaktors (Blasensäule) mit suspendiertem Katalysator bei Gegenstrom von Flüssigkeit und Gas sowie äußerem Gaskreislauf wurden die makrokinetischen Reaktorgleichungen für den stationären, isotherm‐isobaren Fall bei vollständiger Durchmischung der flüssigen Phase aufgestellt. Die experimentelle Prüfung an Hand der als Modellreaktion gewählten Hydrierung von in Schwerbenzin gelöstem n‐Dodecen‐1 an suspendiertem Raney‐Nickel bei Normaldruck ergab, daß sich die Reaktorleistung als Funktion der Betriebsbedingungen aus den abgeleiteten Beziehungen mit ausreichender Genauigkeit vorausberechnen läßt.
Instabile Reaktionszustände bei der heterogenen Katalyse
Authors: Wicke Ewald 
Published: December 2004

AbstractBei stationären Reaktionszuständen offener Systeme in großem Abstand vom chemischen Gleichgewicht können sprunghafte und oszillatorische Instabilitäten auftreten. Für sprunghafte Instabilitäten im Sinne von Zünd/Lösch‐Erscheinungen genügt bereits die Wechselwirkung eines Transportprozesses mit einer chemischen Reaktion von nichtlinearem Verhalten, das entweder thermisch oder kinetisch bedingt sein kann. In Festbettreaktoren spielt bezüglich thermischer Instabilität außer der Einzelkorn‐Instabilität die Rückkopplung durch axialen Wärmetransport eine wesentliche Rolle. Sie bestimmt auch das Verhalten von „wandernden Reaktionszonen”︁.—Oszillatorisches Verhalten (Grenzzyklen) setzt voraus, daß das Reaktionssystem mindestens zwei Speicher für Stoffe bzw. Wärme enthält, die in nichtlinearer Weise miteinander gekoppelt sind. Die Ergebnisse der Untersuchungen am Einzelkorn lassen erkennen, daß der Chemisorption, deren Einfluß bisher unbeachtet geblieben ist, eine zentrale Bedeutung zukommt, da sie einerseits als Transportprozeß wirksam werden, andererseits nichtlineares Reaktionsverhalten verursachen und schließlich bei Oszillationen auch als Speicherkapazität auftreten kann.
Filtrieren, Auswaschen und Entfeuchten feindisperser Feststoffe
Authors: Bender Wolfgang 
Published: December 2004

AbstractDie üblicherweise benutzten Gleichungen zur Beschreibung des Vorgangs der Kuchenfiltration sind nur ausreichend bei relativ einfachen Trennaufgaben. Es gibt eine Reihe von Einflüssen, die zusätzlich berücksichtigt werden müssen; die unmittelbare Übertragung der Ergebnisse von Laborversuchen auf technische Apparate ist in der Regel problematisch. Dies verführt den Praktiker dazu, sich ausschließlich auf seine Erfahrung und auf teuere technische Versuche zu verlassen. Die Lücke zwischen wissenschaftlicher Durchdringung und praktischer Anwendung erscheint bei diesem Fachgebiet besonders groß. An einigen Beispielen aus dem Bereich der industriellen Anwendung — Auswaschen von Filterkuchen, Entfeuchten von Filterkuchen in einer Zentrifuge, Klärfiltration — wird gezeigt, daß theoretische Überlegungen in Verbindung mit systematischen Laborversuchen dennoch zu Aussagen führen können, die auch für andere Stoffsysteme der Praxis und für die technische Anwendung interessant sind. Die Eigenschaften des mechanisch mehr oder weniger entfeuchteten Filterkuchens sind von großem Einfluß auf die apparative Ausführung von Trennapparaten. Hier sind bisher nur qualitative Beschreibungen möglich.
Fließverhalten von Schüttgütern in Bunkern
Authors: Schwedes Jörg 
Published: December 2004

AbstractBeim Fließen von Schüttgütern in Bunkern unterscheidet man zwischen Massenfluß und Kernfluß. Von der Art des Flusses werden unter anderem die Verweilzeit, die Möglichkeit von Entmischungen nach der Teilchengröße oder Teilchendichte und die Konstanz der Auslaufmassenströme beeinflußt. Bei Kenntnis der Reibungsverhältnisse im Schüttgut und an der Bunkerwand und der Druckfestigkeit des Schüttgutes unter Berücksichtigung der Lagerzeit können Bunker so dimensioniert werden, daß befriedigende Auslaufverhältnisse erzielt und Brücken‐ und Schachtbildungen vermieden werden. Es wird dargelegt, wie die Schüttguteigenschaften zu messen sind und der Bunker diesen angepaßt wird. Austraghilfen sind nötig, wenn reiner Schwerkraftfluß nicht zu erwarten ist. Mit bekannten Schüttguteigenschaften können unbefriedigend arbeitende Bunkeranlagen verbessert werden.
Mechanismen der Haftkraftverstärkung bei der Partikelhaftung durch plastisches Verformen, Sintern und viskoelastisches Fließen
Authors: Rumpf Hans , Sommer Karl , Steier Klaus 
Published: December 2004

AbstractHaftkraftverstärkungen treten augenblicklich und im Laufe der Zeit ein. Augenblickliche Haftkraftverstärkungen beruhen auf Umlagerungen und plastischer Verformung. Die Haftkräfte selbst sind im allgemeinen hierfür nicht ausreichend, dagegen können äßere Kräfte — wie Versuche von Schütz und Schubert mit Kalksteinpartikeln zeigten — erhebliche Verstärkungen bis zu einer Größenordnung bewirken. Zeitbedingte Haftkraftverstärkungen beruhen auf viskoelastischer Abplattung und Sinterung. Am System Kugel/Kugel wurden beide Mechanismen theoretisch und experimentell untersucht. Unterhalb einer kritischen Zeit überwiegt die viskose Abplattung, oberhalb das Sinterhalswachstum, das von der Grenzflächenspannung und dem äußeren Anpreßdruck angetrieben werden kann. Die von der Theorie gelieferten quantitativen Zusammenhänge stehen unter Berücksichtigung des hypothetischen Modellcharakters in gutem Einklang mit den experimentellen Befunden.
Auswahlkriterien für nichtkatalytische Gas/Feststoff‐Hochtemperaturreaktoren
Authors: Reh Lothar 
Published: December 2004

AbstractAusgehend von einem Überblick über Reaktortypen für die Durchführung von Gas/Feststoff‐Reaktionen werden mit besonderer Betonung des Bereichs der Hochtemperatur‐reaktionen verschiedene Auswahlkriterien für die Wahl des geeigneten Reaktortyps diskutiert. Im einzelnen sind dies: Strömungsverhalten und Relativgeschwindigkeit Gas/Feststoff in durchströmten Schichten, Temperatursteuerung bei endothermen und exothermen Reaktionen, Reaktionsfläche Gas/Feststoff, Wärme‐ und Stoffaustausch sowie das Reaktionsverhalten der Feststoffe. Anhand dieser Kriterien, die sich an Beispielen aus der Praxis orientieren, wird die Bedeutung der Auswahl der Korngröße für Reaktoren mit hohen Raum‐Zeit‐Ausbeuten aufgezeigt.
Experimental programming of life histories: Toward an experimental science of individual differences
Authors: Denenberg Victor H. , Whimbey Arthur E. 
Published: January 2005

AbstractFour experimental variables were combined in a 2 × 2 × 2 × 2 factorial design. These were (1) infantile handling vs. no handling of the mothers of the subjects, (2) infantile handling vs. no handling of the subjects, (3)rearing of the subjects in either a maternity cage or a free environment between birth and weaning, and (4) rearing of the subjects in either a laboratory cage or a free environment between weaning and 42 days of age (N = 6 Purdue‐Wistar rats per group). Starting at 220 days of age, the groups were given a battery of tests which measured emotional reactivity, exploratory behavior, and consumption‐elimination. Analysis of the criterion data revealed the following: (1) handling pups in infancy reduced emotional reactivity and this reduction was found to be invariant with respect to different combinations of life history experiences; (2) exploratory behavior was markedly influenced by the animal's pattern of life experiences; (3) when mothers were handled during their infancy, their offspring explored significantly less than offspring of nonhandled mothers.
Travel vision in infant monkeys: Maturation rate and abnormal stereotyped behaviors
Authors: Berkson Gershon , Karrer Rathe 
Published: January 2005

AbstractThree monkeys with travel vision and 5 controls were observed with their mothers during the first 6 months of age and then for another 3 months after they had been placed in social isolation. In the home cage, the experimental animals did not differ from controls except that two held a hand before their eyes in a stereotyped fashion not previously reported for animals. In an unfamiliar environment the blind animals did not look at an observer, threatened less than normal, and were awkward in moving around. Animals who held hands before eyes tended to approach a flickering visual stimulus.
The postnatal development of behavioral states in the rat
Authors: Gramsbergen A. , Schwartze P. , Prechtl H. F. R. 
Published: January 2005

AbstractThe ontogeny of behavioral state cycles in white rats has been studied from their 2nd to their 30th day of life. A scale of 5 behavioral states, based on operationally defined categories was employed: state 1: quiet sleep; state 2: active sleep; state 3: quiet wakefulness; state 4: active wakefulness and state 5: locomotion. The percentage of time which young rats spend awake is 2% on the 2nd day, increases then and remains at about 40–60% after the 11th day. Until the 10th day the total sleep time is equally distributed between active sleep and quiet sleep state. After that day a decrement in the relative amount of active sleep occurs. The mean duration of single epochs spent in state 1 increases from less than 1 min on the first days to 6–8 min at about the 25th day. State 2 and state 4 epochs increase only slightly whereas state 3 and state 5 epochs do not show a particular trend.
Prenatal psychological stress and offspring behavior in rats and mice
Authors: Archer John E. , Blackman Derek E. 
Published: January 2005

AbstractThe experimental literature on the behavioral sequelae of prenatal stress in rodents is reviewed, from which few conclusions can be drawn except that some change in activity‐reactivity may be induced. Were more careful consideration given to certain methodologic dimensions, greater clarity of empirical relations could be achieved. These dimensions are: (1) the sex, species, and strain of animal observed; (2) the specification of the prenatal manipulation; and (3) the precision and completeness of the behavioral description which is the dependent variable studied. Multiple descriptions, as in a test‐battery approach, appear to be inefficient and generally unwarranted.
Early experience, ultrasonic vocalizations, and maternal responsiveness in rats
Authors: Bell Robert W. , Nitschke Werner , Bell Nancy J. , Zachman Thomas A. 
Published: January 2005

AbstractFollowing a 2‐min exposure to 5–6°c, neonatal rats emit ultrasounds for about 5 min, resulting in effective maternal care. Five minutes of 5–6°C, causes prolonged ultrasonic vocalizations and correlated agitation in the mothers. The nonlinear effects of variable intensities of neonatal stimulation appear to related to these differences in maternal behavior.
The effect of butylated hydroxyanisole and butylated hydroxytoluene on behavioral development of mice
Authors: Stokes John D. , Scudder Charles L. 
Published: January 2005

AbstractThe chronic ingestion of .5% butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT) by pregnant mice and their offspring resulted in a variety of behavioral changes. Compared to controls, BHA‐treated offspring showed increased exploration, decreased sleeping, decreased self‐grooming, slower learning, and a decreased orientation reflex. BHT‐treated offspring showed decreased sleeping, increased social and isolation‐induced aggression, and a severe deficit in learning.
Neonatal adrogen treatment and sexual behavior in males of three inbred strains of mice
Authors: Vale Jack R. , Ray Donald , Vale Carol A. 
Published: January 2005

AbstractMale neonates of the A, BABL/c, and C57BL/6 mouse strains were injected with androgen and the effects upon their sex behavior studied. Genotype and treatment combined interactively on a number of variables, particularly in the proportions of animals responding, indicating that the effects of perinatally administered androgen and genotype cannot be considered separately.
Effects of cohabitation with females on aggressive behavior between male mice
Authors: Goyens Jacqueline , Noirot Eliane 
Published: January 2005

AbstractIndividual male mice of several groups were observed during daily encounters with a male intruder. The groups differed with regard to social and sexual experience of the resident animal and of the intruder. Aggressive behavior was most intense in residents actually living with a female and least intense in sexually naïve residents living alone. Residents that had only once cohabited with a female for a short time obtained intermediate scores. Experienced intruders were attacked less than naïve ones.
Changes in lateral differentiation of head posture in the human neonate
Authors: Turkewitz Gerald , Creighton Susan 
Published: January 2005

AbstractDevelopmental changes in the relationship between lateral differences in responsiveness and the assumption of asymmetrical head postures were examined. The head turning of 70 infants ranging in age from 0–72 hr was observed following a procedure (maintenance of the head in a midline position) known to reduce or eliminate lateral differences in the infant's response to stimulation. Even following this procedure infants older than 12 hr made significantly more right than left head turns whereas younger infants exhibited no such difference. When lateral differences in sensitivity were not interfered with in 0 to 12 hr old infants (n = 20) they, kile the older infants, made significantly more right than left turns. These results are discussed in terms of possible developmental consequences of a reciprocity between asymmetric head position and lateral differences in sensitivity.
The pineal gland and the development of salt intake patterns in male rats
Authors: Křeček Jiří 
Published: January 2005

AbstractThe effect of gonadectomy, sham‐gonadectomy, pinealectomy, and sham‐pinealectomy on the concentration of NaCl in the total volume of fluid drunk per day ([NaCl]I) in male rats offered a free choice between water and 3% saline was measured. Neonatal gonadectomy increased [NaCl]I in adult males but had no effect on immature rats. If the rats, however, were neonatally pinealectomized as well as gonadectomized, the increase of [NaCl]I also appeared in the immatures. Neonatal sham‐pinealectomy decreased [NaCl]I in immature and adult rats, both gonadectomized and sham‐gonadectomized. In adult neonatally gonadectomized males the effects of sham‐pinealectomy did not occur in those animals actually pinealectomized. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to the function of hypothalamus, neonatal stress, and sexual maturation.
Self‐conscious behavior of infants: A videotape study
Authors: Amsterdam Beulah , Greenberg Lawrence M. 
Published: January 2005

AbstractThe reactions of 4 infants each at ages 10, 15, and 20 months were recorded on videotape as they responded to their own simultaneous video image, their own previously taped video image, the image of a control infant, and that of a female stranger. The subjects' responses were coded by 2 research assistants, ignorant of the original stimuli and the purpose of the study. The following behavioral categories were used: attends, sociable behavior, curiosity, unhappiness‐withdrawal, and self‐consciousness. The 1st‐step discriminant according to a matrix algebra analysis between age groups was self‐conscious behavior in response to the simultaneous video image. Twenty month‐old infants were significantly different in their display of self‐consciousness from the 10 and 15 month‐old groups; the latter did not differ from each other.
Aversive prenatal stimulation: Effects on behavioral, biochemical, and somatic ontogeny in the rat
Authors: Sobrian Sonya K. 
Published: January 2005

AbstractElectric foot shock administered to pregnant rats altered the ontogeny of spontaneous motor activity in their pups. Prenatally stimulated (PMS) offspring were more active than controls on Days 1–10 but less active during the 3rd postpartum week. The age of peak activity, a major developmental landmark, occurred in PMS pups around 10 days of age; in controls maximum activity was not seen until the 3rd week. This effect was independent of the gender of the offspring and the timing of the gestational stimulation. Its appearance in both cross‐fostered and fostered pups indicated the prenatal origin of the effect. The maturation of spontaneous alternation behavior and several reflexes and the appearance of physical features were not affected by prenatal stimulation. Moreover, both PMS and control groups exhibited an age‐related increase in brain concentrations of norepinephrine, serotonin, and 5‐hydroxyindoleacetic acid. These findings indicate that spontaneous motor activity is uniquely sensitive to PMS, and as far as can be determined here, PMS produces no generalized alternation in behavioral and physical ontogeny.
Interaction of separation distress with fear in infant dogs
Authors: Davis Kenneth L. , Gurski John C. , Scott J. P. 
Published: January 2005

AbstractForty‐one Telomian, beagle, and F1 hybrid puppies were tested in the presence and absence of a sound‐producing stimulus under 2 social conditions, single and paired, at 6, 7, and 8 weeks of age. The sound stimulus definitely produced fearful reactions, as measured by tail carriage, which were not affected by social condition and accompanying differences in distress vocalization. Nor was distress vocalization significantly altered by the sound stimulus. We conclude that sound‐induced fear and separation distress are separate and independent affective states. Social condition and the presence of the sound stimulus produced interactive effects at the behavioral level in that paired animals showed longer latencies to contact and maintained greater distances from the sound stimulus.
Early learning and retention of a conditioned taste aversion
Authors: Ader Robert , Peck Jack H. 
Published: January 2005

AbstractWeanling rats were trained on a taste aversion task and tested 60 days later using the single bottle and preference methods for assessing the retention of a taste aversion, and a competitive situation in which the CS was eventually substituted for plain water. Only the competitive situation showed the effects of the early taste aversion training. The results are discussed in terms of the conditioning and reactivation of adrenocortical steroid elevations and how these might affect subsequent retrieval.
Rooting and the development of male sexual behavior in two inbred mouse strains
Authors: D'Udine Bruno , Manning Aubrey 
Published: January 2005

AbstractThe sexual development of C57BL 6/J and SEC/IReJ male mice was studied during twice‐weekly pairings with estrus females from 5 weeks of age. SEC were far slower to begin copulating than C57 and their responses to the female included a much higher frequency of rooting. Rooting, where the male's snout is pushed below the female's flank and jerked upwards, declines over tests as the full copulatory pattern develops. SEC also spent a higher proportion of their time in close contact with the female and groomed her more than C57. Both strains showed more rapid development of copulation if testing was delayed until 10 weeks of age, especially if they had exposure to female scent during this maturation period. The frequency of rooting and the speed of development are inversely related in these strains, but in segregating hybrid populations no such relationship is maintained.It is argued that the slowness of SEC's development cannot be ascribed to low sexual motivation. The significance of rooting remains obscure, but it seems possible that it may represent an aspect of exploratory behavior that is highly developed in SEC and some other strains.
Brain growth in young mice: Evidence on the theory of phrenoblysis
Authors: Hahn Martin E. , Walters James K. , Lavooy Jacqueline , Deluca John 
Published: January 2005

AbstractBrain growth was studied from day of birth through 23 days of age in three outbred and one inbred groups of mice. The results showed that the brain grows rapidly from Birth through 11 days and quite slowly thereafter. We found no evidence of the several spurts and plateaus in growth that are central to the theory of phrenoblysis (correlated brain and mind growth). Our results show the main features of mouse brain growth to parallel those of human brain growth except of timing of rapid and slow growth.
Ontogenesis of learning: I. Variation in the rat's reflexive and learned responses to gustatory stimulation
Authors: Vogt Mark B. , Rudy Jerry W. 
Published: January 2005

AbstractThese experiments indicate that by Day 15 after birth, the processes that mediate a number of taste‐controlled behaviors in the rat are functional. These include the sensory processes necessary to detect and respond reflexively to sucrose, the event‐learning processes that reduce the rat's neophobic reaction to sucrose, and the integrative‐learning processes that enable it to learn an aversion to sucrose when paired with lithium toxicosis, even when these events are separated by 1 hr. These capacities, however, did not emerge simultaneously. Those necessary to detect and respond reflexively to sucrose emerged prior to those that contribute to the learned control of taste‐guided behaviors. It is argued that these age‐related dissociations in behavioral capacities reflect a caudal‐to‐rostral maturational sequence of components of the ascending gustatory system that are thought to underlie these capacities.
Nonnutritive, thermotactile induction of filial huddling in rat pups
Authors: Alberts Jeffrey R. , May Brad 
Published: January 2005

AbstractNorway rat pups, 15 days of age and older, huddle preferentially with members of their own species. This normal filial response can be reassigned, however, by altering the olfactory characteristics of the mother. The present series of experiments was designed to isolate those aspects of maternal stimulation that establish the filial huddling preferences of rat pups. Results of two‐choice huddling tests indicated that daily, 4‐hr exposures to a perfumed foster dam induced filial preferences for odors associated with maternal care. Similar effects were also achieved with equal amounts of “mere exposure” (familiarization) to odors. Different kinds of odor‐experience pairings were evaluated with a within‐subject regime of alternating, daily exposures. It was found that preferences induced by maternal contact are stronger than those resulting from familiarization. We rejected the hypothesis that the nursing relationship is necessary or contributory factor in the establishment of the rat's filial attraction; preferences for odors associated with a nonlactating foster mother were as strong as those derived from maternal contact that included nutritive foster mother were as strong as those derived maternal contact that included nutritive nursing. Contact interactions with an inanimate, warm, scented tube induced preferences as strong as those induced by maternal care. It was concluded that thermotactile stimulation during mother‐young interactions induces olfactory preferences in the weanling rat.
Kittens as therapists: Social behavior sequences in isolated squirrel monkeys after exposure to young nonconspecifics
Authors: Huebner Douglas K. , King James E. 
Published: January 2005

AbstractSquirrel monkeys that had been exposed to repeated separations from cloth surrogates were given continuous access to domestic kittens. Information‐theoretic measures showed that these monkeys exerted greater constraint on behaviors of adult feral squirrel monkeys than did monkeys who had not received previous kitten exposure. The latter monkeys displayed a behavioral encapsulation characterized by increased susceptibility to the constraint imposed by their own preceding behaviors and a decreased susceptibility to constraint from other monkeys' behavior. In addition, kitten‐reared monkeys displayed a hig level of positive social behaviors, particularly following noncohesive or divisive behaviors by another monkey.