A NEW VENEROID GENUS (MOLLUSCA: BIVALVIA) OF THE DANIAN OF PATAGONIA (CHUBUT PROVINCE, ARGENTINA)

The endemic Patagonian genus Titomaya gen. nov. is erected to include the Danian Meretrix chalcedonica (Lefipan and Salamanca formations) and T. longobucca sp. nov. (Salamanca Formation) from the Chubut Province (Argentina). Although Meretrix and Titomaya share the same characteristic sculpture of their nymphs, Titomaya is differentiated by having medium to small, subtriangular, higher than long shells, a narrower and shorter hinge plate, smaller cardinal and anterior teeth, and by the development of a deeper pallial sinus. This new genus rules out the presence of Meretrix in Patagonia as long believed and increases the list of endemic taxa that characterize the Danian assemblages of Patagonia.

The earliest fossil record of the poorly known family Condylocardiidae from Argentina

The scarcely known family Condylocardiidae (Bivalvia: Archiheterodonta) is poorly represented in the fossil record and their living representatives are also poorly known. This work presents a new representative of the family from the early Pliocene of marine terrace of Cerro Laciar (Santa Cruz Province). Carditella pitufina sp. nov. is described and characterized by a shell large for the genus, 15 radial ribs as wide as interspaces, high hinge plate and broad and large hinge teeth. The poor record of the family may be due to an identification bias, probably because the tiny size of specimens and its similarity with carditids. This new species resembles to the living Carditella tegulata from southern Argentina and Chile and they could be closely related. Carditella pitufina sp. nov. represents the most ancient record of Carditella in South America and the most ancient record of Condylocardiidae in Argentina.

Damage Identification Algorithm of Hinged Joints for Simply Supported Slab Bridges Based on Modified Hinge Plate Method and Artificial Bee Colony Algorithms

Hinge joint damage is a typical form of damage occurring in simply supported slab bridges, which can present adverse effects on the overall force distribution of the structure. However, damage identification methods of hinge joint damage are still limited. In this study, a damage identification algorithm for simply supported hinged-slab bridges based on the modified hinge plate method (MHPM) and artificial bee colony (ABC) algorithms was proposed by considering the effect of hinge damage conditions on the lateral load distribution (LLD) of structures. Firstly, MHPM was proposed and demonstrated, which is based on a traditional hinge plate method by introducing relative displacement as a damage factor to simulate hinge joint damage. The effectiveness of MHPM was verified through comparison with the finite element method (FEM). Secondly, damage identification was treated as the inverse problem of calculating the LLD in damage conditions of simply supported slab bridges. Four ABC algorithms were chosen to solve the problem due to its simple structure, ease of implementation, and robustness. Comparisons of convergence speed and identification accuracy with genetic algorithm and particle swarm optimization were also conducted. Finally, hinged bridges composed of four and seven slabs were studied as numerical examples to account for the feasibility and correctness of the proposed method. The simulation results revealed that the proposed algorithm could identify the location and degree of damaged joints efficiently and precisely.

Error cascade in taxonomy: The case of Cardiomya perrostrata (Mollusca: Bivalvia: Cuspidariidae) in Brazilian waters

Successions of erroneous taxonomic identifications in biodiversity studies are an undesirable but not rare phenomenon. Such cascades of errors frequently involve taxa with few, polymorphic diagnostic characters, such as representatives of the cuspidariid genus Cardiomya. Four species of the genus are believed to live in Brazilian waters: C. cleryana (d’Orbigny, 1842), C. ornatissima (d’Orbigny, 1853), C. striata (Jeffreys, 1876) and C. perrostrata (Dall, 1881). Many reported occurrences of these species are based on misidentifications, but the error cascade of incorrect records of C. perrostrata is by far the most extensive. Although the species has been reported to live in Brazilian waters for about half a century, all previous records seem to be based on a succession of mistaken identifications. This paper redescribes C. perrostrata based on an analysis of the type series, several lots of museum vouchers and new material collected in the Campos Basis (Rio de Janeiro, Brazil). Ontogenetic changes in shell outline and ultrastructural details of the hinge plate, periostracal surface and larval shell are described and illustrated for the first time. Based on a critical appraisal of the literature, we present an updated geographic and bathymetric distribution of the species. Cardiomya perrostrata displays a gradual increase in the relative length of the rostrum during its ontogeny and in larger specimens the rostrum is more prominently curved upwards. The larval shell is of type 2D, measuring about 215–235 μm in length. The periostracum is minutely pitted and a lithodesma is present. Its distribution is Western Atlantic, ranging from 42°N to 30°S, in depths of 18 to 1646–1829 m. Cardiomya knudseni (Allen & Morgan, 1981), a possibly related amphi-Atlantic species whose type material has been lost, is regarded herein as a nomen dubium.

A Numerical Investigation of a Novel Hood Design for Pedestrian Protection

Currently the use of new materials is becoming even more prevalent in vehicle industry for the lightweight design purpose. The design of engine hood is very important for pedestrian’s safety during a vehicle-pedestrian accident. In order to improve the pedestrian protection performance of the new material engine hood, the radial stiffening rib structure and trapezium sandwich structure engine hoods were proposed in this paper. And an energy-absorbing structure has been designed on the strengthening hinge plate to reduce the pedestrian head injury further more. The simulation results indicate that with new structures, the new material engine hoods have more uniform rigidity and better energy absorbing ability, which would effectively reduce the engine hood intrusion and pedestrian head injuries.

Conchological Variability of Anadara Inaequivalvis (Bivalvia, Arcidae) In the Black–Azov Sea Basin

Conchological Variability of Anadara inaequivalvis (Bivalvia, Arcidae) in the Black-Azov Sea Basin. Anistratenko, V. V., Anistratenko, O. Yu., Khaliman, I. A. - An alien species in the Black Sea and the Sea of Azov - Anadara inaequivalvis (Bruguiere, 1789) - was recently discovered to have a wide range of shell variability. From the investigated samples (over 900 valves) six basic types of the shell commissural opening were defined; they are not, however, discrete conditions. Th e presence of intermediate variants reveals a gradual (continuous) character of the shell variability and indicates that all the samples investigated belong to the same species. Th e variation of some other Anadara characteristics is also discussed, including: quantity and ornamentation of the ribs on the surface of the valves, quantity of chevrons on the ligament area, shape of the hinge plate and quantity of hinge teeth. A comparison of conchological characteristics of Anadara from the Black-Azov Sea Basin with A. inaequivalvis from southeast India shows that ranges and patterns of shell variability of Azov-Black Sea Anadara correspond to variability of A. inaequivalvis from this species type locality - Coromandel Coast of India.

Аналіз роботи орного агрегату з трактором МТЗ-80 із диференціальним і блокованим міжколісним приводом

Представлені результати експериментального дослідження роботи орного агрегату в складі трактора МТЗ-80 та навісного плуга на супіща-ному ґрунті з диференціальним та блокованим міжколісним приводом заднього моста. В резуль-таті аналізу отриманих нами експериментальних даних встановлено, що з блокованим приводом до-тична сила тяги трактора зростає у межах від 3,99 до 21,5 % порівняно з диференціальним приво-дом. Зростання дотичної сили відбувається за рахунок збільшення обертаючого моменту на пра-вому колесі, що знаходиться в борозні. Додаткова сила тяги використовується для переборення зростаючої сили опору руху агрегату. Блокований міжколісний привід призводить до погіршення керованості трактора та збільшення витрати палива в середньому на 12 %. Для підтримання прямолінійного руху агрегату необхідно тримати передні колеса трактора повернутими вправо; до того ж із блокованим приводом кут повороту коліс зростає. The results of experimental research of work of arable aggregate are presented in composition of the tractor of МТZ-80 and hinge-plate plough on sandy-loam soil at the differential and blocked interwheeled drive of back bridge. It is set as a result of analysis of the obtained data that at the blocked drive tangent tractive of tractor force increases in limits from 3, 99 to 21, and 5 % as compared to a differential drive. The increase of tangent force takes place due to the increase of twisting moment on a right wheel that is in a furrow. Additional tractive force is used for overcoming of increasing force of resistance to motion of aggregate. The blocked interwheeled drive results in worsening of dirigibility of tractor and increase of expense of fuel on the average on 12 %. For maintenance of rectilineal motion of aggregate it is necessary to retain the forewheels of tractor turned to the right, thus, at the blocked drive the corner of turn of wheels increases.