Apparent Absorption Research Articles

Preparation of artificial aggregate using waste concrete powder and CO2 fixed by microorganisms

High carbon emissions, shortages of natural aggregates and environmental pollution of waste concrete powder (WCP) have become open issues for the traditional concrete industry. Aggregates prepared by crushing and screening waste concrete usually possess poor mechanical properties. Meanwhile, the WCP cannot be effectively utilized. This paper proposes a novel approach based on microorganisms for strengthening mechanical properties and improving CO2 sequestration of ‘newly’ artificial aggregates prepared by cold-bonding pelletization of WCP. Specifically, the microorganisms enhanced the artificial aggregates, resulting in their apparent density, crushing strength and water absorption increasing to 2620 kg/m3, 9.1 MPa and 4.8%, respectively. With the increase of well-crystallized mineralization products, the artificial aggregates exhibited a denser microstructure where the porosity decreased from 20.9 to 13.9%. The CO2 fixation of artificial aggregates increased from 7.4 to 16.0 wt. % due to the existence of microorganisms. The compressive strength of concrete indicated that artificial aggregate could partially substitute the natural aggregates without affecting its strength, and a better substitution rate should be controlled within 50%. This method improves waste resource utilization and CO2 emission reduction, showing good potential for future applications.Graphical abstractPreparation process of the artificial aggregate and its application.

Lightweight foam concrete containing expanded perlite and glass sand: Physico-mechanical, durability, and insulation properties

Foam concrete refers to a type of concrete with high porosity that can be produced with or without aggregate. Foam concrete has generally superior thermal insulation properties compared to conventional concrete. Despite its major thermal benefits, the high content of Portland cement, as well as its very high porosity, makes foam concrete prone to physico-durability concerns such as drying shrinkage by allowing the entrance of chemicals and free water to the concrete pores. To address this and reduce the pore network connectivity, in this study, expanded perlite and fine-sized waste glass sand were used as the main aggregates in concrete mixes. In that respect, 10 mixes of foam concrete were produced with two foam contents of 50 and 100 kg/m3, with a constant water-to-binder ratio (w/b) of 0.5. In each mix, the dominated expanded perlite aggregate was replaced by waste glass sand having a size of < 2.36 mm. Apparent porosity, water absorption, compressive and flexural strength, sorptivity, ultrasonic pulse velocity (UPV), drying shrinkage, freeze–thaw, alkali-silica reaction, thermal conductivity, and thermal resistance tests were performed to investigate the physico-mechanical, durability and insulation properties of the foam concrete. Based on the results, it is found that the addition of glass sand improves physico-mechanical and durability properties of foam concrete. The addition of expanded perlite increases the insulating properties of foam concrete, potentially due to the high porosity of expanded perlite compared to that of glass sand. The findings of this study point to the suitability of producing sustainable insulating foam concrete through the use of waste glass sand.

The calcium supplementation effect of calcium-binding oligopeptides from bonito (Auxis thazard) hydrolysate in rats

Sixty Ca-deficient male Wistar rats were divided into six groups to investigate the effect of a calcium-binding bonito hydrolysate (PBH-Ca) on calcium bioavailability in rats, including the normal group, the control groups (PBH + CaCO3 group and the CaCO3 group), and three PBH-Ca groups with doses of 2,000 (PBH-Ca-H group), 1,000 (PBH-Ca-M group), and 500 (PBH-Ca-L group) mg/kg body wt/day. Each group was given the corresponding drug by intragastric administration for 4 weeks. The indices measured included the rate of increase in body weight and body length, apparent calcium absorption rate, serum calcium, serum phosphorus, alkaline phosphatase (ALP) activity, bone volume fraction (BV/TV), bone mineral density (BMD), and trabecular microstructure of the rats scanned by micro-computed tomography. The results showed that PBH-Ca promoted the growth of rats, significantly increased the apparent calcium absorption rate and the number of bone trabeculae, stabilized serum calcium and serum phosphorus content in serum, significantly inhibited ALP activity, decreased the separation of bone trabeculae, accelerated bone growth of rats, and raised the BV/TV and femoral BMD in the rats. These results illustrate that PBH-Ca has promising potential in a high-quality calcium diet.

Спектрофотометрическое определение ионовCo(II) сN-(2-гидроксибензоил)-N'-(п-тозил)гидразином в аммиачных средах

A technique has been developed for the spectrophotometric determination of Co(II) ions with N-(2-hydroxybenzoyl)-N'-(p-tosyl)hydrazine (GBSH) in an ammonia medium. The absorption spectra of the reagent and its complex with Co(II) ions have been recorded and analyzed. The optimal conditions for the formation of the complex compound were found: the pH range of complex formation; optimal time for color development; amount of photometric reagent. Under optimal conditions for the complexation of GBSG with Co(Ⅱ) ions, a calibration graph was constructed. The Bouguer-Lambert-Beer law is fulfilled in the range from 0.3 to 2.4 mg Co(II) in 25 ml of solution. The true and apparent molar light absorption coefficients were calculated. The true molar coefficient of light absorption of the complex compound GBSG with Co(Ⅱ) ions in an ammonia medium is 750. The molar ratios in the solution of the complex compound [Co(Ⅱ)]:[GBSG] = 1:1 and 1:2. The conditional stability constant of the GBSG complex with Co(Ⅱ) ions was calculated using the Babko method and it is 3.24∙1012. The convergence and correctness of the spectrophotometric technique were determined by the method of mathematical statistics.

Evaluation of the use of açaí seed residue as reinforcement in polymeric composite

Açaí ( Euterpe oleracea Mart.) is an important economic source in the north region of Brazil for agro-industry. However, it generates a huge amount of seed residue as agro-waste. The aim of this study is to evaluate the performance of this residue as reinforcement in particleboards. The medium-density particleboards were manufactured according to the experimental design (22 + 1), considering the parameters with two factors: “Granulometry”, for different açaí seed sizes (2.38, 1.19, 0.29, 0.15 and 0.07 mm) and “%Resin”, for different resin weight fractions (10%, 12.5% and 15%), both applied in the manufacturing of the composites. Measurements for the Apparent Density Thickness Swelling and Water Absorption (WA) of the particleboards were performed. Mechanical properties of particleboards were analyzed through top and surface Screw Withdrawal and Internal Bonding test. In addition, the morphology of surface from particleboards was evaluated through Scanning Electron Microscopy The results of TS for 24 h, WA for 2 and 24 h, and IB showed that the particle size was a significant factor ( p &lt; .05). These results established that the highest particle sizes provided lower percentages of absorption. The results of Screw Withdrawal did not achieve the requirements established by NBR 14810–2:2018 standard. Besides that, the results presented statistical difference, considering the particle size and the interaction between parameters (“%Resin” and “Granulometry”), which resulted in a p-value &lt; .05. For the Internal Bonding test, the composite with highest particle size exhibited the best performance compared to the other ones.

PROPRIEDADES DA MADEIRA LAMINADA CRUZADA COLADA COM ADESIVO À BASE DE TANINOS DA CASCA DAS ÁRVORES DE Mimosa Tenuiflora

ABSTRACT This study aimed to determine the concentration of condensed tannins in the bark of Mimosa tenuiflora (Willd) Poir trees. Additionally, the physical-mechanical properties of cross-laminated timber (CLT) panels bonded with an adhesive based on M. tenuiflora tannins were assessed. Bark was collected from five trees. The adhesive formulation was synthesized by mixing powdered tannins, paraformaldehyde, and water at 50 °C under continuous stirring. Bark tannins extract in its pristine state without any previous chemical treatment or modification was employed to synthesize the adhesive. Viscosity, pH, solids content, and gel time of the adhesive formulation were determined. CLT panels were manufactured with Eucalyptus spp. wood. The bonding performance was assessed by determining the physical (apparent density and water absorption) and mechanical (modulus of elasticity – MOE, modulus of rupture – MOR, and shear strength) properties of the CLT panels. Condensed tannins content in the M. tenuiflora bark was 23.4%. Adhesive properties were pH = 3.93, TS of 50.64%, gel time of 460 s, and 6,000 cP for viscosity. Values of MOE, MOR and shear strength were 4,411, 16.18, and 1.06 MPa, respectively. The M. tenuiflora tannins are promising for the formulation of adhesives to bond CLT.

Bio-based polyurethane resin: An ecological binder for a novel class of building materials-composites

A novel application for mineral-filled composites with a bio-based polyurethane resin (BPR) binder was previously proposed to reduce the construction industry's carbon footprint. However, more details over the binder degradation conditions are necessary to clarify the composite usage in new sustainable building materials. Therefore, this work analyzed a castor oil-based polyurethane binder by its physical indexes (NBR 15845), mechanical properties (ASTM D 695), alterability by chemical reagents (ASTM D 543), humid atmosphere attack (NBR 8095), UV-rays exposure (ASTM G 53), thermogravimetry (TG/DTG), and differential scanning calorimetry (DSC). Besides, specimens of vermiculite/BPR composite were produced to evaluate the binder performance. BPR proved to be lightweight (1.19 g.cm−3) with a near-zero apparent porosity and water absorption. BPR was resistant to weathering action, while a slight variation in elastic modulus was detected during chemical attack. A thermal-stable filler is recommended for the building material application.

Effects of expanded vermiculite on the properties of fired bricks from water treatment sludge

AbstractIn the present study, the suitability of using water treatment sludge (WTS) as the main raw material and expanded vermiculite (EV) as aggregate in the production of fired bricks was investigated. Mixtures containing between 75%–100% WTS by weight (wt.) and 5%–25% EV by wt. were prepared at various proportions. The mixtures were compressed under 40 MPa pressure and fired at 1000°C. It was found the incorporation of EV in fired bricks resulted in a decrease in thermal conductivity, compressive strength, and bulk density and an increase in apparent porosity and water absorption. For the addition of 5%–25% EV by wt., bulk density ranged between 2.01 and 1.69 kg/m3, compressive strength 19.3 and 8.3 MPa, water absorption 21.1% and 10.1%, and thermal conductivity 0.678 and 0.374 W/m‐K, respectively. Based on the promising physical and mechanical properties, fired bricks incorporating WTS and EV can potentially offer an alternative to the traditional production of clay bricks while adhering to the principle of a circular economy.

Solvated Electron in Acetonitrile: Radiation Yield, Absorption Spectrum, and Equilibrium between Cavity- and Solvent-Localized States.

The equilibrium between a solvent cavity-localized electron, ecav-, and a dimeric solvent anion, (CH3CN)2•-, which are the two lowest energy states of the solvated electron in acetonitrile, has been investigated by pulse radiolysis at 233-353 K. The enthalpy and entropy for the ecav- to (CH3CN)2•- conversion amount to -11.2 ± 0.3 kcal/mol and -39.3 ± 1.2 cal/(mol K), corresponding to a 0.44 ± 0.35 equilibrium constant at 25 °C. The radiation yield of the solvated electron has been quantified using a Co(II) macrocycle that scavenges electrons with a 1.55 × 1011 M-1 s-1 rate constant. The apparent yield increases without saturation over the attainable scavenger concentration range, reaching 2.8 per 100 eV; this value represents the lower limit for the acetonitrile ionization yield in pulse radiolysis. The apparent molar absorption coefficient of (20.8 ± 1.5) × 103 M-1 cm-1 at 1450 nm and 20 °C for the solvated electron and individual vis-near-infrared (NIR) absorption spectra of ecav- and (CH3CN)2•- are derived from the data. Variances with previous reports are thoroughly discussed. Collectively, these results resolve several controversies concerning the solvated electron properties in acetonitrile and furnish requisite data for quantitative pulse radiolysis investigations in this commonly used solvent.

Effects of aflatoxin B1 and monensin interaction on liver and intestine of poultry – influence of a biological additive (Pichia kudriavzevii RC001)

The aim of this study was to evaluate the effects of aflatoxin B1 (AFB1) and monensin (MONS) interaction on the liver and intestinal histological changes in poultry, and the influence ofPichia kudriavzevii RC001. One-day-old commercial line (Ross 308) broilers (n=120) were individually weighed and randomly assigned to 8 treatments (15 broilers/treatment, 5 broilers per cage and 3 replicates/treatment). The experimental diets were: Group 1: basal diet (BD); Group 2: BD + MONS (50 mg/kg); Group 3: BD +P. kudriavzevii RC001 (1 g/kg); Group 4: BD + AFB1 (100 μg/kg); Group 5: BD + MONS +P. kudriavzevii RC001; Group 6: BD + AFB1 +P. kudriavzevii RC001; Group 7: BD + AFB1 + MONS +P. kudriavzevii RC001; Group 8: BD + AFB1 + MONS. When MONS was added, the typical AFB1 macroscopic and microscopic alterations were intensified. TheP. kudriavzevii RC001 cytotoxicity and genotoxicity assays with Vero cells and with broiler chicken’s erythrocytes, demonstrated thatP. kudriavzevii RC001 neither were non-cytotoxic nor genotoxic. When MONS was added in the presence ofP. kudriavzevii RC001, the toxic effect of AFB1 on liver was not prevented. WhenP. kudriavzevii was present alone, the same prevention of the pathological damage was observed in the intestine of poultry fed with AFB1. The smallest apparent absorption area was obtained when AFB1 and MONS were added in the feed (P&lt;0.05). AFB1 and MONS interaction demonstrated important toxic effects. AlthoughP. kudriavzevii was effective in ameliorating the adverse effects of AFB1 alone on liver pathology and gut morphology, it was not able to diminish the toxic effects of AFB1 in presence of MONS. It suggests thatP. kudriavzevii could be used as feed additive or counteracting the toxic effects of AFB1 in poultry production in the absence of MONS.

Evaluación de recursos en el estudio de las propiedades industriales y culinarias para la caracterización varietal de arroz (Oryza sativa L.)

Different physicochemical tests have been used over time in the Oryza sativa species for the study of industrial and culinary properties. In this study, nine attributes were compared: amylose content, total whiteness, thousand grain weight, grain length and width, gelatinization time, apparent water absorption, expansion ratio, and gelatinization temperature. However, there is no single attribute that allows defining the concept of “culinary quality” in rice, since it depends on its behavior after cooking. The two varieties of long fine polished rice used for this study were: IRGA 424 (Rio Grandense Rice Institute) and Tranquilo FL INTA (National Institute of Agricultural Technology) and a mixture of both. In this work, the characterization of industrial and culinary properties of the rice varieties mentioned above was achieved by evaluating five attributes using simple and low-cost physical-chemical techniques in two of the rice varieties most in demand by producers in the province of Corrientes. This finding would allow the study of rice varieties to be approached by optimizing: equipment, reagents and time in future trials.

Effect of Boron Supplementation on Nutrient Utilization and Productive Performance of Peripartum Murrah Buffaloes.

Boron (B) has been established as a beneficial micronutrient for some farm animals. However, its impact on coping negative energy balance during transition and subsequent production performance needs critical perusal. Therefore, the present study was undertaken to determine the effect of B supplementation on productive performance, apparent nitrogen (N), and mineral utilization in peripartum Murrah buffaloes. Thirty advanced pregnant buffaloes (60days prior to expected date of calving) were allocated into three groups, i.e. control, B-200, and B-400, and supplemented with pharmacological concentration of B at 0, 200, and 400ppm, respectively, from 45days prior to expected date of calving till 120days post calving. Two metabolism trials were conducted (with animals having similar expected date of calving), one during prepartum (30days prior to the expected date of calving) and another during postpartum (90days post calving) phase to evaluate nutrient utilization and balance of N as well as minerals. Results revealed that B supplementation decreased (P < 0.05) overall plasma nonesterified fatty acids (NEFA), whereas plasma level of β-hydroxybutyric acid, insulin, triglyceride, and glucose did not differ (P > 0.05) among the groups. Dry matter intake, nutrient digestibility, and N balance remained unaffected with B supplementation. Higher (P < 0.05) apparent absorption coefficient for magnesium (Mg) and zinc (Zn) was observed in pregnant animals, while during lactation, absorption coefficient of calcium, Mg, and Zn was increased (P < 0.05) in B-supplemented groups. Hence, it can be concluded that alteration in NEFA concentration and variation in apparent absorption coefficient of minerals with B supplementation suggest its role in energy and mineral metabolism. However, further investigations are required to determine the underlying mechanism of action for the present findings.

Experimental investigation of a light extinction based sensor assessing particle size and distribution in an oil system

Optical particle counters (OPCs) based on the light extinction measurement scheme are widely used in the industry for monitoring the level of wear debris in lubricating oil systems. In this work it is investigated how model-based size estimation and OPC output data can be correlated. Spherical metal coated 5–20 μm diameter particles were used in a laboratory oil system and monitored using an OPC. The raw OPC output data were extracted with the purpose of estimating the true particle size. Distribution parameters has been deducted from detected minima in output signals for each particle diameter using a half-normal fit centered at the detected kernel peak. Experiments with different sized particles showed that signal minima amplitude distributions differ between particle diameters thus, clearly showing the discrimination ability of the OPC. Furthermore, to obtain OPC based true size determination, the apparent absorption coefficient of the micrometer sized particles must be considered. Thus, reducing the maximum deviation between true and OPC determined diameter to 13%.

Preparation and In Vitro and In Vivo Evaluation Of Panax Notoginseng Saponins-loaded Nanoparticles Coated with Trimethyl Chitosan Derivatives

In this study, novel Panax notoginseng saponins (PNS)-loaded nanoparticles coated with the Trimethyl chitosan (TMC) derivatives TMC-VB12 and TMC-Cys (PPTT-NPs) were developed to improve the oral absorption of the constituents. PPTT-NPs were prepared by the double emulsion method and showed different encapsulation effects on the major components, including Rg1, Rb1, and R1, in PNS. In vivo, the absorption rate constant and apparent absorption coefficient of PPTT-NPs were higher than PNS solution. These findings preliminarily proved that PPTT-NPs can promote intestinal absorption to a certain extent. The pharmacokinetic results indicated that the blood concentration and the area under the curve of Rg1 and Rb1 in the PPTT-NPs were higher than Xueshuantong capsules. The cell viability of PPTT-NPs was above 90% within 25-150 μg/mL. PPTT-NPs promoted the cellular uptake of PNS by receptor-mediated endocytosis. In summary, NPs coated with TMC-VB12 and TMC-Cys can be used as promising drug delivery systems.

Molecular structure, quantum chemical and spectroscopic properties of 2,6–dibromonaphthalene by density functional theory calculations

In this work, the quantum chemical calculations were performed by means of the Gaussian09 packet program, using DFT in gas phase at the B3LYP level, with cc-pVDZ, cc-pVTZ, 6-31G(d,p) and 6-311G(d,p) basis sets. The most stable conformation of the 2,6–dibromonaphthalene (2,6–DBrN) molecule in free state was determined by the Spartan'14 program. The vibrational frequencies have been calculated at the same level of theory. These frequencies were calculated and scaled, and then values have been compared with the experimental Infrared and Raman spectra. The vibrational modes were determined based on TED analysis on the basis of 6-311G(d,p) using the SQM program. Theoretical 13C–NMR and 1H–NMR chemical shifts of the 2,6–DBrN molecule were calculated in DMSO and were compared the experimental values. NBO analysis study of 2,6–DBrN was performed to investigate charge transfer as well as to analyzed intra- and interactions. The HOMO and LUMO energy levels of the 2,6–DBrN molecule were determined. Besides, molecular electrostatic potential (MEP) maps of the studied molecule were made using the DFT method. Since the apparent absorption maxima of the molecules correspond to the electron transitions between the boundary orbitals corresponding to the HOMO–LUMO energies, these transitions were analyzed by UV/Visible spectroscopy.

Histories and Memories of the Liberation War: Saranarthis in Tripura

In the twentieth century, South Asia experienced mass migrations of millions of insecure homeless people twice: it witnessed the Partition-refugees from 1947 and saranarthis during the liberation war of 1971. The Indian State treated the first category as ‘citizen-refugees’, whereas the saranarthis were like temporary shelter-seekers. Among the Northeastern states, Tripura played the most crucial role in providing them with all essential supports. Taken as a case study, this article tries to locate the inner dynamics behind the apparent absorption process in Tripura and it aims to argue that the experience was complex and two-fold in nature for both the communities.

Preparation and compression performance of porous magnesium alloy composite with ceramic hollow spheres

Using two different ceramic hollow spheres (the commercial alumina hollow sphere and the self-made silicon-containing ceramic hollow sphere) as reinforcements, two kinds of lightweight porous magnesium alloy composite materials were successfully fabricated by sintering at 600 °C for 3 h 20 min. The microstructure of samples with the self-made silicon-containing ceramic hollow sphere reveals that an alloy phase containing MgO and Mg2Si was formed by an interfacial reaction at the interface between the magnesium alloy and the self-made ceramic hollow sphere. The formation of the alloy phase is beneficial to improve the mechanical properties of the sample. The influence of different types of ceramic hollow spheres on the apparent density, compressive strength, specific strength, energy absorption, and energy absorption efficiency was studied for these porous products. The results show that the apparent density of these two porous samples is markedly lower than that of the magnesium alloy. The Compression curves of both samples have the elastic stage, the yield platform, and the densification stage, which are the typical compression characteristics of porous materials. The compressive strength and specific strength of the samples made by self-made silicon-containing ceramic hollow spheres are both significantly higher than those made by commercial alumina hollow spheres. Moreover, the energy absorption performance of the sample made by self-made silicon-containing ceramic hollow spheres is better than that of the sample made by alumina hollow spheres. The higher energy absorption capacity and the wider strain range of maintaining the maximum energy absorption efficiency mean the sample made by self-made silicon-containing ceramic hollow spheres can absorb more energy.

Valorization of granite micronized stones wastes for eco-friendly production of fired clay bricks

Construction and mining industries around the globe have been criticized for production of enormous solid wastes that have potential environmental impacts. Therefore, this study presents a feasible approach to recover and utilize granite micronized stones waste for production of eco-friendly bricks. This research work, aimed at substituting a natural clay with granite powder to produce value-added bricks with pronounced physical–mechanical properties. The micronized granite waste stones were crushed and ground to obtain a fine powder sample. Thereafter, different batch compositions containing a varied proportions of granite powder were prepared and fired at different sintering temperatures: 900, 1000 and 1100 °C. The raw materials and bricks were characterized for their chemical compositions, microstructural, mineralogical and physical–mechanical properties. The results showed that, an increase in granite waste powder and sintering temperature enhanced the quality of fired clay bricks in terms of mechanical strength and decreased simultaneously the apparent porosity and water absorption. The final experimental approach showed that, the possibility to produce eco-friendly bricks containing up to 30 wt% of granite powder with enhanced engineering properties fired at 1100 °C is promising.Graphic abstract

143 Effect of Supplementary Selenium Source on Dairy Cow Performance, Antioxidant Status, and Apparent Absorption and Retention

Abstract The objective of this experiment was to determine how source of selenium (Se) affects dairy cow performance, antioxidant status, and apparent absorption and retention. Multiparous Holstein cows (n = 24; 597 ± 49 kg BW) were blocked by days in milk (161 ± 18) and randomly assigned to receive 0.3 mg/kg of either: 1) organic Se (selenized yeast; ORG; Sel-Plex-Alltech); or, 2) inorganic Se (sodium selenite; INO) premix, top dressed and mixed into a ration daily. After an 11-week adaptation period (blood and milk sampled monthly), cows received an intraruminal dose of Se77 (either Se77 yeast or NaSe77O3) followed by a 4-day period of blood and rumen fluid sampling, and total collection of feces, urine, and milk. Data were analyzed using PROC GLIMMIX in SAS with fixed effects of treatment, time, and their interaction, and random effect of block. Daily DMI (23 ± 0.6 kg), milk yield (35 ± 1.2 kg), plasma glutathione peroxidase (64 ± 4.2 U), and serum Se (0.11 ± 0.003 µg/g) were not different between treatments during the adaptation period. Serum Se77 maximum concentration and area under the curve (AUC) were not different between treatments for 72 hours following infusion, but rumen fluid Se77 AUC was higher (P = 0.02) for ORG cows. Apparent absorption (64 ± 1.3%) and retention (44 ± 1.5%) of the Se77 dose did not differ between treatments. The ORG cows had lower urinary excretion (13 vs. 17 ± 0.6%; P &amp;lt; 0.01), higher milk excretion (6 vs. 2 ± 0.3%; P &amp;lt; 0.01), and similar fecal excretion (36 ± 1.3%; P = 0.9) of Se77 compared to INO cows. These results indicate that ORG Se increased Se content of milk and decreased Se excretion in urine, but did not alter performance, antioxidant status, and apparent absorption and retention of Se in mid-lactation cows.

Prepartum level of dietary cation-anion difference fed to nulliparous cows: Acid-base balance, mineral metabolism, and health responses

Objectives were to determine the effects of 3 different levels of dietary cation-anion difference (DCAD) fed during the last 22 d of gestation to pregnant nulliparous cows on pre- and postpartum acid-base balance, mineral metabolism, and health responses. In all, 132 pregnant nulliparous Holstein cows were enrolled at 250 (248-253) d of gestation, blocked by genomic merit of energy-corrected milk yield, and assigned randomly to diets varying in DCAD: +200 (P200, n = 43), -50 (N50, n = 45), or -150 (N150, n = 44) mEq/kg of dry matter. Dietary treatments were fed until calving, after which cows received the same lactation diet for the first 100 d postpartum. Urine and blood were sampled throughout the prepartum period and in the first weeks postpartum, and urine was assessed for pH, whereas blood was analyzed for gases, measures of acid-base balance, minerals, and metabolites. Calcium (Ca) and magnesium (Mg) retention and phosphorus (P) digestibility were evaluated in the last week of gestation and first week of lactation. Incidence of diseases was evaluated for the first 100 d postpartum. Data are presented in sequence as P200, N50, N150 (LSM ± SEM). Reducing the DCAD reduced urine (8.17 vs. 6.50 vs. 5.51 ± 0.11) and blood pH (7.442 vs. 7.431 vs. 7.410 ± 0.004) and induced a state of compensated metabolic acidosis with a reduction in blood HCO3- (28.4 vs. 26.7 vs. 24.9 ± 0.3 mM) and partial pressure of CO2 (41.8 vs. 40.1 vs. 39.1 ± 0.4 mmHg) prepartum. Reducing the DCAD linearly increased blood ionized Ca (iCa; 1.224 vs. 1.243 vs. 1.259 ± 0.008 mM) and serum total Ca (tCa; 2.50 vs. 2.53 vs. 2.56 ± 0.02 mM) prepartum, blood iCa on the day of calving, and serum Mg in the first days postpartum. Reducing the DCAD linearly increased the apparent absorption of Ca (12.9 vs. 19.0 vs. 20.9 ± 1.4 g/d) and Mg (7.0 vs. 9.9 vs. 10.4 ± 1.4 g/d) prepartum, but apparent retention of both Ca (13.9 g/d) and Mg (3.4 g/d) did not differ with treatment. Treatment did not affect digestibility of P pre- or postpartum or retention of Ca or Mg postpartum. Treatment did not affect the incidence or prevalence of subclinical hypocalcemia, hepatic composition, or the prevalence of fatty liver. Reducing the DCAD had a quadratic effect on incidence of fever (46.5 vs. 17.6 vs. 33.9 ± 7.0%), uterine diseases (36.3 vs. 25.6 vs. 46.0 ± 7.3%), and morbidity (41.4 vs. 28.1 vs. 55.6 ± 7.3%). Feeding a diet with -50 mEq/kg of dry matter promoted moderate changes in acid-base balance, altered mineral metabolism, and benefited health of nulliparous cows; however, further reducing the DCAD to -150 mEq/kg negated the benefits to health.